IP L3VPN over SRv6 uses SRv6 tunnels to carry IP L3VPN services. This technology establishes SRv6 tunnels among geographically dispersed customer sites over an IPv6 network and transparently forwards Layer 3 customer traffic to remote sites over the IPv6 network through the tunnels. For more information about MPLS L3VPN configuration, see MPLS Configuration Guide.

Basic principle

Figure 1 shows a typical IP L3VPN over SRv6 network.

· PE 1 and PE 2 use BGP to advertise IPv4 or IPv6 VPN routes to each other over the IPv6 backbone network. The VPN routes contain private network routing information and SID information.

· The PEs have a single-hop SRv6 tunnel between them and they use the SRv6 tunnel to forward VPN traffic across sites.

· The devices in the IPv6 backbone network forward the SRv6-encapsulated VPN traffic through the optimal path calculated by IGP.

IP L3VPN over SRv6 connects geographically dispersed sites that belong to the same VPN over the IPv6 backbone network.

If the customer sites belong to the public network, IP L3VPN over SRv6 takes the public network as a special VPN. The PEs establish a single-hop SRv6 tunnel between them and use the SRv6 tunnel to forward public network traffic across sites. This scenario is also called the public network over SRv6 scenario.

Figure 1 Network diagram

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Route advertisement

The route advertisement process of IPv4 L3VPN over SRv6 is similar to that of IPv6 L3VPN over SRv6. This section uses IPv4 L3VPN over SRv6 to illustrate the process.

As shown in Figure 1, local routes of CE 1 are advertised to CE 2 by using the following process:

1. CE 1 uses static routing, RIP, OSPF, IS-IS, EBGP, or IBGP to advertise routes of the local site to PE 1.

2. After learning the route information of CE 1, PE 1 stores the private routes to the routing table of the VPN instance. In this example, VPN instance 1 is used. Then, PE 1 converts the routes to BGP VPNv4 routes and advertises the BGP VPNv4 routes to PE 2 by using MP-BGP. The BGP VPNv4 routes carry the RD, RT, and SID attributes (the SID attribute is used as the private network label).

¡ If next hop-based dynamic SID allocation is not used, all private network routes of the VPN instance are allocated the same End.DT4 or End.DT46 SID.

¡ If next hop-based dynamic SID allocation is used, private network routes with the same next hop are allocated the same End.DX4 SID in the VPN instance.

3. When PE 2 receives the routes advertised by PE 1, it adds the routes to the routing table of VPN 1, converts the routes to IPv4 routes, and advertises the IPv4 routes to CE 2.

4. By adding the received IPv4 routes to the routing table, CE 2 learns the private network routes of CE 1.

Packet forwarding

IP L3VPN over SRv6 supports the following route recursion modes:

· SRv6 BE mode.

· SRv6 TE mode.

· SRv6 TE and SRv6 BE hybrid mode.

· SRv6 TE and SRv6 BE FRR mode.

The packet forwarding process differs by the route recursion mode in use.

SRv6 BE mode

This mode is also called SID-based forwarding mode. In this mode, a PE forwards an SRv6 packet by searching the IPv6 routing table based on the SRv6 SID encapsulated in the packet.

The packet forwarding process is similar for IPv4 L3VPN over SRv6 and IPv6 L3VPN over SRv6. This section uses IPv4 L3VPN over SRv6 and VPN sites to illustrate the process.

As shown in Figure 1, CE 2 forwards an IPv4 packet to CE 1 as follows:

1. CE 2 sends the IPv4 packet to PE 2.

2. PE 2 receives the packet on an interface associated with the VPN instance (in this example, the VPN instance is VPN 1). PE 2 searches for a route that matches the destination IPv4 address of the packet in the routing table of the VPN instance. The corresponding End.DT4, End.DT46, or End.DX4 SID is found. Then, PE 2 encapsulates an outer IPv6 header for the packet. The End.DT4, End.DT46, or End.DX4 SID is encapsulated in the outer IPv6 header as the destination address.

3. PE 2 searches the IPv6 routing table based on the End.DT4, End.DT46, or End.DX4 SID for the optimal IGP route and forwards the packet to P through the route.

4. P searches the IPv6 routing table based on the End.DT4, End.DT46, or End.DX4 SID for the optimal IGP route and forwards the packet to PE 1 through the route.

5. When PE 1 receives the packet, it processes the packet as follows:

¡ If the packet header contains an End.DT4 or End.DT46 SID, PE 1 searches the local SID forwarding table for the SID and removes the outer IPv6 header. Then, PE 1 matches the packet to VPN 1 based on the SID, searches the routing table of VPN 1 for the optimal route, and forwards the packet to CE 1.

¡ If the packet header contains an End.DX4 SID, PE 1 searches the local SID forwarding table for the SID and removes the outer IPv6 header. Then, PE 1 forwards the packet to CE 1 according to the next hop and output interface bound to the SID.

SRv6 TE mode

This mode is also called SRv6 TE policy-based forwarding mode. In this mode, when a PE forwards a customer packet, it first searches for a matching SRv6 TE policy based on the packet attributes. Then, the PE adds an SRH to the packet. The SRH includes the destination SRv6 SID and the SID list of the SRv6 TE policy. Finally, the PE forwards the encapsulated packet based on the SRv6 TE policy.

The following modes are available to steer traffic to an SRv6 TE policy:

· Color—The device searches for an SRv6 TE policy that has the same color and endpoint address as the color and nexthop address of a VPN route. If a matching SRv6 TE policy exists, the device recurses the VPN route to that SRv6 TE policy. When the device receives packets that match the VPN route, it forwards the packets through the SRv6 TE policy.

· Tunnel policy—The device searches the tunnel policies for a matching SRv6 TE policy based on the next hop of a matching route. Configure a preferred tunnel or load sharing tunnel policy that uses the SRv6 TE policy. In this way, the SRv6 TE policy will be used as the public tunnel to forward the packets of private network packets.

For more information about tunnel policies, see MPLS Configuration Guide. For more information about SRv6 TE policies, see "Configuring SRv6 TE policies."

SRv6 TE and SRv6 BE hybrid mode

In this mode, the PE preferentially uses the SRv6 TE mode to forward a packet. If no SRv6 TE policy is available for the packet, the PE performs IPv6 routing table lookup based on the encapsulated SRv6 SID, and forwards the packet in SRv6 BE mode.

SRv6 TE and SRv6 BE FRR mode

This mode implements FRR by using the SRv6 TE path (primary path) and SRv6 BE path (backup path). If the SRv6 TE path (SRv6 TE policy) fails or does not exist, traffic is immediately switched to the SRv6 BE path to ensure service continuity. This mode reduces the path convergence time after the route recursion mode is changed.

SRv6 multilevel FRR (primary SRv6 TE path > backup SRv6 TE path > primary SRv6 BE path > backup SRv6 BE path)

This mode implements multilevel FRR by using multiple SRv6 TE and SRv6 BE paths for faster traffic protection. The FRR primary path consists of one primary SRv6 TE path and one backup SRv6 TE path. The FRR backup path consists of one primary SRv6 BE path and one backup SRv6 BE path. The device selects the traffic forwarding path in primary SRv6 TE path, backup SRv6 TE path, primary SRv6 BE path, and backup SRv6 BE path order.

SRv6 multilevel FRR (primary SRv6 TE path > primary SRv6 BE path > backup SRv6 TE path > backup SRv6 BE path)

This mode implements multilevel FRR by using multiple SRv6 TE and SRv6 BE paths for faster traffic protection. The FRR primary path consists of one primary SRv6 TE path and one primary SRv6 BE path. The FRR backup path consists of one backup SRv6 TE path and one backup SRv6 BE path. The device selects the traffic forwarding path in primary SRv6 TE path, primary SRv6 BE path, backup SRv6 TE path, and backup SRv6 BE path order.

IP L3VPN over SRv6 FRR

IMPORTANT:

IP L3VPN over SRv6 FRR is supported only when the customer sites belong to VPNs.

IP L3VPN over SRv6 Fast Reroute (FRR) is applicable to a dualhomed scenario, as shown in Figure 2. By using static BFD to detect the primary link, FRR enables a PE to use the backup link when the primary link fails. The PE then selects a new optimal route, and uses the new optimal route to forward traffic.

IP L3VPN over SRv6 supports VPNv4 route backup for a VPNv4 route and VPNv6 route backup for a VPNv6 route.

Figure 2 Network diagram of VPNv4 route backup for a VPNv4 route

IPv4 L3VPN over SRv6 and IPv6 L3VPN over SRv6 use the same FRR mechanism. This section uses VPNv4 route backup for a VPNv4 route as an example to illustrate the mechanism.

As shown in Figure 2, configure FRR on the ingress node PE 1, and specify the backup next hop for VPN 1 as PE 3. When PE 1 receives a VPNv4 route to CE 2 from both PE 2 and PE 3, it uses the route from PE 2 as the primary link, and the route from PE 3 as the backup link.

Configure static BFD for public tunnels on PE 1 to detect the connectivity of the public tunnel from PE 1 to PE 2. When the tunnel PE 1—PE 2 operates correctly, traffic from CE 1 to CE 2 goes through the path CE 1—PE 1—PE 2—CE 2. When the tunnel fails, the traffic goes through the path CE 1—PE 1—PE 3—CE 2.

In this scenario, PE 1 is responsible for primary link detection and traffic switchover.

For more information about static BFD, see BFD configuration in High Availability Configuration Guide.

Restrictions and guidelines: IP L3VPN over SRv6 configuration

In the current software version, the device does not support End.DX4 or End.DX6 SIDs and associated application scenarios.

IP L3VPN over SRv6 tasks at a glance

To configure IP L3VPN over SRv6, perform the following tasks:

1. Configuring a VPN instance and associating interfaces connected to CEs with the VPN instance

Perform this task on PEs. For more information, see MPLS L3VPN in MPLS Configuration Guide.

2. Configuring route exchange between a PE and a CE

Configure an IPv4 routing protocol (static routing, RIP, OSPF, IS-IS, EBGP, or IBGP) or an IPv6 routing protocol (IPv6 static routing, RIPng, OSPFv3, IPv6 IS-IS, EBGP, or IBGP) to exchange routes between a PE and a CE

On the CE, configure an IPv4 or IPv6 routing protocol to advertise routes of the local site to the PE. On the PE, associate the routing protocol with the VPN instance. For more information about routing protocol configurations, see Layer 3—IP Routing Configuration Guide.

3. Configuring route exchange between PEs

a. Configuring an SRv6 SID

Perform this task to manually configure an End.DT4, End.DT6, End.DT46, End.DX4, or End.DX6 SID.

b. Applying a locator to a BGP VPN instance

BGP can advertise SRv6 SIDs through BGP routes only after you apply a locator to BGP.

c. Configuring PEs to exchange BGP VPNv4 or VPNv6 routes

d. Configuring IPv6 peers to exchange SRv6 SIDs

This feature enables PEs to exchange End.DT4, End.DT6, End.DT46, End.DX4, or End.DX6 SIDs through BGP VPNv4 or VPNv6 routes.

e. (Optional.) Configuring BGP VPNv4 or VPNv6 routes

4. Configuring the route recursion mode

5. Specifying a source address for the outer IPv6 header of SRv6-encapsulated packets

This feature specifies the source address of the outer IPv6 header for SRv6 packets that are delivered between two sites over the backbone network.

6. (Optional.) Enabling SRv6 VPN compatibility for a peer or peer group

7. (Optional.) Configuring IP L3VPN over SRv6 FRR

8. (Optional.) Configuring SBFD for SRv6 locators

9. (Optional.) Configuring a TTL processing mode for tunnels associated with a VPN instance

Configuring an SRv6 SID

Restrictions and guidelines

If PEs advertise BGP VPNv4 or VPNv6 routes to each other, you must specify a VPN instance when configuring an opcode.

Procedure

1. Enter system view.

system-view

2. Enable SRv6 and enter SRv6 view.

segment-routing ipv6

3. Configure a locator and enter SRv6 locator view.

locator locator-name [ ipv6-prefix ipv6-address prefix-length [ args args-length | static static-length ] * ]

4. Configure an opcode. Perform one of the following tasks:

¡ Configure an End.DT4 SID.

opcode { opcode | hex hex-opcode } end-dt4 [ vpn-instance vpn-instance-name ]

The specified VPN instance must exist. An End.DT4 SID cannot be configured in different VPN instances.

¡ Configure an End.DT6 SID.

opcode { opcode | hex hex-opcode } end-dt6 [ vpn-instance vpn-instance-name ]

The specified VPN instance must exist. An End.DT6 SID cannot be configured in different VPN instances.

¡ Configure an End.DT46 SID.

opcode { opcode | hex hex-opcode } end-dt46 [ vpn-instance vpn-instance-name ]

The specified VPN instance must exist. An End.DT46 SID cannot be configured in different VPN instances.

Applying a locator to a BGP VPN instance

About this task

This feature is applicable to an IP L3VPN over SRv6 network with VPN sites. Use this feature in BGP-VPN IPv4 or IPv6 unicast address family view of a VPN instance to apply for SRv6 SIDs for the private network routes of the VPN instance.

Use this feature if the device will use End.DT4, End.DT6, End.DT46, End.DX4, or End.DX6 SIDs to deliver VPN traffic across sites.

Restrictions and guidelines

The VPN instance of the specified locator must be the same as the VPN instance of the private network. To specify a VPN instance for a locator, use the opcode end-dt4, opcode end-dt6, opcode end-dt46, opcode end-dx4, or opcode end-dx6 command in SRv6 locator view.

Prerequisites

Before you perform this task, you must create the specified locator.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP-VPN instance view.

ip vpn-instance vpn-instance-name

4. Enter BGP-VPN IPv4 unicast address family view or BGP-VPN IPv6 unicast address family view.

¡ Enter BGP-VPN IPv4 unicast address family view.

address-family ipv4 [ unicast ]

¡ Enter BGP-VPN IPv6 unicast address family view.

address-family ipv6 [ unicast ]

5. Apply a locator to the BGP VPN instance.

segment-routing ipv6 locator locator-name [ auto-sid-disable | auto-sid-dt46 ]

By default, no locator is applied to a BGP VPN instance.

Configuring PEs to exchange BGP VPNv4 or VPNv6 routes

Restrictions and guidelines

For more information about the commands in this section, see BGP in Layer 3—IP Routing Command Reference.

To ensure optimal route selection and SRv6 tunnel traffic forwarding, make sure a pair of PEs are not both IPv4 and IPv6 peers to each other.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Specify a remote PE as an IPv6 peer.

peer { group-name | ipv6-address [ prefix-length ] } as-number as-number

4. Specify a source interface (IPv6 address) for establishing TCP connections to an IPv6 peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } connect-interface interface-type interface-number

By default, BGP uses the output interface in the optimal route destined for a BGP peer or peer group as the source interface for establishing TCP connections.

5. Create the BGP VPNv4 or VPNv6 address family and enter its view.

¡ Create the BGP VPNv4 address family and enter its view.

address-family vpnv4

¡ Create the BGP VPNv6 address family and enter its view.

address-family vpnv6

6. Enable BGP to exchange VPNv4 or VPNv6 routing information with an IPv6 peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } enable

By default, BGP cannot exchange VPNv4 or VPNv6 routing information with an IPv6 peer or peer group.

Configuring IPv6 peers to exchange SRv6 SIDs

About this task

Perform this task to configure IPv6 peers to exchange SRv6 SID information through BGP VPNv4, VPNv6, IPv4 unicast, or IPv6 unicast routes.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Enable BGP to exchange SRv6 SID information with an IPv6 peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } prefix-sid

By default, BGP cannot exchange SRv6 SID information with an IPv6 peer or peer group.

Configuring BGP VPNv4 or VPNv6 routes

Restrictions and guidelines for BGP VPNv4 or VPNv6 route configuration

For more information about the commands in this section, see BGP in Layer 3—IP Routing Command Reference.

Controlling BGP VPNv4 or VPNv6 route advertisement and reception

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Set the maximum number of routes that BGP can receive from a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } route-limit prefix-number [ { alert-only | discard | reconnect reconnect-time } | percentage-value ] *

By default, the number of routes that BGP can receive from a peer or peer group is not limited.

5. Save all route updates from a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } keep-all-routes

By default, route updates from peers and peer groups are not saved.

Setting a preferred value for received BGP VPNv4 or VPNv6 routes

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Set a preferred value for routes received from a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } preferred-value value

By default, the preferred value is 0 for routes received from a peer or peer group.

Configuring BGP VPNv4 or VPNv6 route reflection

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Configure the router as a route reflector (RR) and specify a peer or peer group as its client.

peer { group-name | ipv6-address [ prefix-length ] } reflect-client

By default, no RR or client is configured.

5. (Optional.) Enable route reflection between clients.

reflect between-clients

By default, route reflection between clients is enabled.

6. (Optional.) Configure the cluster ID of the RR.

reflector cluster-id { cluster-id | ip-address }

By default, an RR uses its own router ID as the cluster ID.

7. (Optional.) Create an RR reflection policy.

rr-filter { ext-comm-list-number | ext-comm-list-name }

By default, an RR does not filter reflected routes.

8. (Optional.) Enable the RR to change the attributes of routes to be reflected.

reflect change-path-attribute

By default, the RR cannot change the attributes of routes to be reflected.

Configuring BGP VPNv4 or VPNv6 route attributes

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Configure the NEXT_HOP attribute. Choose one of the following options:

¡ Specify the router as the next hop for routes sent to a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } next-hop-local

¡ Configure the router to not change the next hop of routes advertised to a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } next-hop-invariable

By default, the router sets itself as the next hop for routes sent to a peer or peer group.

5. Configure the AS_PATH attribute.

¡ Permit the local AS number to appear in routes from a peer or peer group and set the appearance times.

peer { group-name | ipv6-address [ prefix-length ] } allow-as-loop [ number ]

By default, the local AS number is not allowed in routes from a peer or peer group.

¡ Remove private AS numbers from the AS_PATH attribute of updates sent to an EBGP peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } public-as-only [ { force | limited } [ replace ] [ include-peer-as ] ]

By default, BGP updates sent to an EBGP peer or peer group can carry both public and private AS numbers.

For more information about the parameters in this command, see BGP in Layer 3—IP Routing Command Reference.

6. Advertise the COMMUNITY attribute to a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } advertise-community

By default, the COMMUNITY attribute is not advertised.

7. Advertise the Large community attribute to a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } advertise-large-community

By default, the Large community attribute is not advertised to a peer or peer group.

8. Configure the SoO attribute for a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } soo site-of-origin

By default, no SoO attribute is configured for a peer or peer group.

Configuring BGP VPNv4 or VPNv6 route distribution filtering policies

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Specify an ACL or IP prefix list to filter advertised BGP routes.

filter-policy { ipv4-acl-number | name ipv4-acl-name | prefix-list prefix-list-name } export [ protocol process-id ]

By default, no ACL or IP prefix list is specified to filter advertised BGP routes.

5. Specify an ACL or IP prefix list to filter received BGP routes.

filter-policy { ipv4-acl-number | name ipv4-acl-name | prefix-list prefix-list-name } import

By default, no ACL or IP prefix list is specified to filter received BGP routes.

6. Specify an IP prefix list to filter BGP routes for a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } prefix-list prefix-list-name { export | import }

By default, no IP prefix list is specified to filter BGP routes for a peer or peer group.

7. Apply a routing policy to routes received from or advertised to a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } route-policy route-policy-name { export | import }

By default, no routing policy is applied to routes received from or advertised to a peer or peer group.

8. Enable route target filtering of received VPNv4 or VPNv6 routes.

policy vpn-target

By default, the route target filtering feature is enabled for received VPNv4 or VPNv6 routes. BGP adds an VPNv4 or VPNv6 route to the routing table only when the export route targets of the route match the local import route targets.

Configuring the BGP Additional Paths feature

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Configure the BGP Additional Paths capabilities.

peer { group-name | ipv6-address [ prefix-length ] } additional-paths { receive | send } *

By default, no BGP Additional Paths capabilities are configured.

5. Set the maximum number of Add-Path optimal routes that can be advertised to a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } advertise additional-paths best number

By default, only one Add-Path optimal route can be advertised to a peer or peer group.

6. Set the maximum number of Add-Path optimal routes that can be advertised to all peers.

additional-paths select-best best-number

By default, a maximum number of one Add-Path optimal route can be advertised to all peers.

7. (Optional.) Set the optimal route selection delay timer.

route-select delay delay-value

By default, the optimal route selection delay timer is 0 seconds, which indicates that optimal route selection is not delayed.

Configuring BGP to preferentially use the routes learned from a peer or peer group

About this task

Perform this task to enable BGP to prefer the routes learned from a specific peer or peer group to the routes learned from other peers or peer groups. This route selection rule has lower priority than the rule that selects the route learned from EBGP, confederation EBGP, confederation IBGP, or IBGP in turn. In addition, this route selection rule has higher priority than the rule that selects the route with the smallest IGP metric.

For more information about BGP route selection rules, see BGP in Layer 3—IP Routing Configuration Guide.

Restrictions and guidelines

This feature takes effect only on BGP routes learned in the address family view where this feature is configured. It cannot take effect on BGP routes imported from other instances or address families.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Configure BGP to preferentially use the routes learned from a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } high-priority [ preferred ]

By default, BGP does not preferentially use the routes learned from a peer or peer group.

Configuring the route recursion mode

About this task

After a PE receives a customer packet destined for an SRv6 SID, it forwards the packet according to the route recursion mode.

· SRv6 BE mode—This mode is also called SID-based forwarding mode. In this mode, the PE first encapsulates the End.DT4, End.DT6, or End.DT46 SID into the packet. Then, the PE searches the IPv6 routing table based on the SID encapsulated in the packet to forward the packet.

· SRv6 TE mode—This mode is also called SRv6 TE policy-based forwarding mode. In this mode, the PE first searches for a matching SRv6 TE policy based on the packet attributes. Then, the PE adds an SRH to the packet. The SRH includes the End.DT4, End.DT6, or End.DT46 SID and the SID list of the SRv6 TE policy. Finally, the PE forwards the encapsulated packet through the SRv6 TE policy. For more information, see "Configuring SRv6 TE policies."

· SRv6 TE and SRv6 BE hybrid mode—To use this mode, specify the best-effort keyword for the command in BGP VPNv4/VPNv6 address family view. In this mode, the PE preferentially uses the SRv6 TE mode to forward the packet. If no SRv6 TE policy is available for the packet, the PE forwards the packet in SRv6 BE mode.

· SRv6 TE and SRv6 BE FRR mode—To use this mode, specify the best-effort keyword for the command in BGP-VPN IPv4/IPv6 address family view. This mode implements FRR by using the SRv6 TE path (primary path) and SRv6 BE path (backup path). If the SRv6 TE path fails or does not exist, traffic is immediately switched to the SRv6 BE path to ensure service continuity.

· SRv6 TE and SRv6 BE multilevel FRR mode

¡ If you specify the best-effort keyword but do not specify the local-preference keyword for the command in BGP-VPN IPv4/IPv6 address family view: This mode implements multilevel FRR by using multiple SRv6 TE and SRv6 BE paths for faster traffic protection. The FRR primary path consists of one primary SRv6 TE path and one backup SRv6 TE path. The FRR backup path consists of one primary SRv6 BE path and one backup SRv6 BE path. The device selects the traffic forwarding path in primary SRv6 TE path, backup SRv6 TE path, primary SRv6 BE path, and backup SRv6 BE path order. This keyword is used in dual-homing scenarios.

¡ If you specify both the best-effort and local-preference keywords for the command in BGP-VPN IPv4/IPv6 address family view: This mode implements multilevel FRR by using multiple SRv6 TE and SRv6 BE paths for faster traffic protection. The FRR primary path consists of one primary SRv6 TE path and one primary SRv6 BE path. The FRR backup path consists of one backup SRv6 TE path and one backup SRv6 BE path. The device selects the traffic forwarding path in primary SRv6 TE path, primary SRv6 BE path, backup SRv6 TE path, and backup SRv6 BE path order. This keyword is used in dual-homing scenarios.

When the route recursion mode is SRv6 BE, SRv6 TE and SRv6 BE FRR, or SRv6 TE and SRv6 BE multilevel FRR, if the locator associated with the SIDs assigned by BGP to routes matches multiple IGP routes (that is, the IGP-advertised locator route has multiple next hops), the BGP route can recurse to multiple SRv6 BE paths. If multiple IGP routes matching the locator form FRR, the multiple SRv6 BE paths obtained through recursion for the BGP route also form the same type of FRR. The rules to form FRR vary by IGP. For more information, see the associated IGP configuration guide.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP-VPN instance view.

ip vpn-instance vpn-instance-name

4. Enter BGP-VPN IPv4 unicast address family view or BGP-VPN IPv6 unicast address family view.

¡ Enter BGP-VPN IPv4 unicast address family view.

address-family ipv4 [ unicast ]

¡ Enter BGP-VPN IPv6 unicast address family view.

address-family ipv6 [ unicast ]

5. Configure the route recursion mode.

segment-routing ipv6 { best-effort | traffic-engineering | traffic-engineering best-effort [ local-preference ] }

By default, a PE searches the IPv6 routing table based on the next hop of a matching route to forward traffic.

Specifying a source address for the outer IPv6 header of SRv6-encapsulated packets

Restrictions and guidelines

To ensure correct traffic forwarding in an IP L3VPN over SRv6 network with VPN or public network sites, you must specify a source address for the outer IPv6 header of SRv6-encapsulated packets.

You cannot specify a loopback address, link-local address, multicast address, or unspecified address as the source IPv6 address. You must specify an IPv6 address of the local device as the source IPv6 address, and make sure the IPv6 address has been advertised by a routing protocol. As a best practice, specify a loopback interface address of the local device as the source IPv6 address.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Specify a source address for the outer IPv6 header of SRv6-encapsulated packets.

encapsulation source-address ipv6-address

By default, no source address is specified for the outer IPv6 header of SRv6-encapsulated packets.

Enabling SRv6 VPN compatibility for a peer or peer group

About this task

In an IP L3VPN over SRv6 network, PE devices from different vendors might use different formats to encrypt SRv6 SIDs in the VPNv4 or VPNv6 routes. As a result, the PE devices might fail to identify the received VPNv4 or VPNv6 routes, causing route advertisement failure. To resolve this issue, you can perform this task to change the SRv6 SID encryption format for BGP routes sent by H3C devices for interoperability with devices from other vendors.

Procedure

1. Enter system view.

system-view

2. Enter BGP instance view.

bgp as-number [ instance instance-name ]

3. Enter BGP VPNv4 address family view or BGP VPNv6 address family view.

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

4. Enable SRv6 VPN compatibility for a peer or peer group.

peer { group-name | ipv6-address [ prefix-length ] } srv6-vpn compatible [ srv6-sid-transposition ]

By default, SRv6 VPN compatibility is disabled for a peer or peer group. The device encapsulates SRv6 SIDs for sent BGP routes in the non-Transposition-Scheme format as defined in RFC 9252.

Configuring IP L3VPN over SRv6 FRR

About this task

This task is applicable to an IP L3VPN over SRv6 network.

MPLS L3VPN over SRv6 FRR enables the device to calculate backup routes for all routes of the current address family to reduce the traffic interruption caused by link or device failures on the backbone. If the device learns two unequal-cost routes destined for the same network from different peers, the optimal route is backed up by the other route. When the optimal route becomes unavailable, the device uses the backup route to forward traffic. At the same time, the device calculates a new optimal route and then uses it to direct traffic forwarding.

By default, a VPN instance IP routing table does not have SRv6 SID route information. As a result, FRR can only use the static BFD session for the locator network address to detect the primary path between PEs. If the address families of multiple VPN instances have used the same locator, FRR in these address families might use the same static BFD session to detect the primary path. Once the BFD session detects that the path is not available, the BGP routes in all these address families will perform path switching simultaneously.

For refined FRR management, the segment-routing ipv6 primary-path-detect sid-bfd command is provided in BGP-VPN IPv4 unicast address family view and BGP-VPN IPv6 unicast address family view. After this command is executed, when the device adds a BGP VPNv4/VPNv6 route that contains an SRv6 SID to a VPN instance IP routing table, it adds the SRv6 SID as the next hop of the route. This allows FRR to automatically and preferentially associate the static BFD session for the SRv6 SID to detect the primary path. Once BFD detects that an SRv6 SID is not reachable, it triggers the BGP routes in only one address family to perform path switching. This mechanism provides a smaller control granularity for FRR.

Restrictions and guidelines

This feature might cause routing loops in certain conditions. Make sure you are fully aware of this feature when you use it on a live network.

The segment-routing ipv6 primary-path-detect sid-bfd command applies only to routes that use the SRv6 BE route recursion mode. If the route recursion mode is SRv6 TE and SRv6 BE hybrid, SRv6 TE and SRv6 BE FRR, or SRv6 TE and SRv6 BE multilevel FRR, this command takes effect only when the SRv6 TE path is not available.

Procedure

1. Enter system view.

system-view

2. Configure static BFD.

bfd static session-name [ peer-ipv6 ipv6-address [ vpn-instance vpn-instance-name ] source-ipv6 ipv6-address [ discriminator local local-value remote remote-value ] [ track-interface interface-type interface-number ] ]

If the segment-routing ipv6 primary-path-detect sid-bfd command is not executed, the addresses specified by the peer-ipv6 ipv6-address option and source-ipv6 ipv6-address option must be the locator subnet addresses advertised by the two peers of the link.

If the segment-routing ipv6 primary-path-detect sid-bfd command is executed, the addresses specified by the peer-ipv6 ipv6-address option and source-ipv6 ipv6-address option can be the SRv6 SIDs assigned by the two peers of the link in the VPN instance.

3. Return to system view.

quit

4. Enter BGP instance view.

bgp as-number [ instance instance-name ]

5. Configure BGP FRR to use the control packet or echo packet mode BFD to detect next hop connectivity for the primary route.

primary-path-detect bfd { ctrl | echo }

By default, BGP FRR uses ARP to detect the connectivity to the next hop of the primary route.

For more information about this command, see BGP commands in Layer 3—IP Routing Command Reference.

6. Enter BGP-VPN IPv4 unicast address family view, BGP VPNv4 address family view, BGP-VPN IPv6 unicast address family view, or BGP VPNv6 address family view.

¡ Execute the following commands in sequence to enter BGP-VPN IPv4 unicast address family view:

ip vpn-instance vpn-instance-name

address-family ipv4 [ unicast ]

¡ Enter BGP VPNv4 address family view.

address-family vpnv4

¡ Execute the following commands in sequence to enter BGP-VPN IPv6 unicast address family view:

ip vpn-instance vpn-instance-name

address-family ipv6 [ unicast ]

¡ Enter BGP VPNv6 address family view.

address-family vpnv6

7. (Optional.) Enable using the static BFD session for the SRv6 SID to detect the reachability of the primary path for SRv6 VPN FRR.

segment-routing ipv6 primary-path-detect sid-bfd

By default, the device detects the reachability of the primary path for SRv6 VPN FRR by using the static BFD session for the locator.

This command can be executed only in BGP-VPN IPv4 unicast address family view or BGP-VPN IPv6 unicast address family view.

8. Enable FRR for the address family.

pic

By default, FRR is disabled for a BGP address family.

On a PE deployed with a VPN instance, as a best practice, configure this command in BGP-VPN IPv4 unicast address family view or BGP-VPN IPv6 unicast address family view.

On the ASBR not deployed with a VPN instance, as a best practice, configure this command in BGP VPNv4 address family view or BGP VPNv6 address family view.

For more information about this command, see BGP commands in Layer 3—IP Routing Command Reference.

Configuring SBFD for SRv6 locators

About this task

As shown in Figure 3, in the IP L3VPN over SRv6 BE scenario, CE 2 is dual homed to PE 2 and PE 3. After you enable FRR on PE 1, a primary path and a backup path are generated on PE 1. When the primary path fails, you can configure this feature for fast traffic switchover to the backup path. Use SBFD to detect connectivity of the SRv6 locator (next hop address obtained through route recursion for the private network route) advertised by PE 2 to fast locate primary path failures and switch traffic over to the backup path.

Figure 3 Using SBFD to detect SRv6 locators in a dual-homed network

SBFD detects the connectivity of SRv6 locators as follows:

2. PE 1 sends SBFD packets as the initiator. The SRv6 locators are the destination addresses of the SBFD packets. The IP address specified in the sbfd source-ipv6 command is used as the source IP address of SBFD packets.

3. When PE 2 and PE 3 receive the SBFD packets as reflectors, they compare the remote discriminators in the packets with the locally configured discriminators.

¡ If they are consistent, the reflectors send SBFD response packets to the initiator through IPv6 routes.

¡ If they are inconsistent, the reflectors drop the received SBFD packets.

4. If the initiator can receive SBFD response packets before the detection timer expires, it determines that the SRv6 locators are reachable. If not, the initiator determines that the SRv6 locators are unreachable, and switches over to the backup path.

Restrictions and guidelines

To have this feature take effect, execute the sbfd destination ipv6 remote-discriminator command on PE 1 to configure the mappings between the detected SRv6 locators and remote discriminators. In addition, execute the sbfd local-discriminator command on PE 2 and PE 3 to configure the local discriminators on the reflector end. Make sure PE 1 have consistent discriminator settings with PE 2 and PE 3. For more information about the sbfd destination ipv6 remote-discriminator and sbfd local-discriminator commands, see BFD commands in High Availability Command Reference.

Procedure

1. Enter system view.

system-view

2. Enter SRv6 view.

segment-routing ipv6

3. Configure SBFD for SRv6 locators.

locator-sbfd enable [ template template-name ] [ prefix-list prefix-list-name ]

By default, SBFD is not configured for SRv6 locators.

Configuring a TTL processing mode for tunnels associated with a VPN instance

About this task

A tunnel associated with a VPN instance supports the following TTL processing modes:

· Pipe—When an IP or IPv6 packet enters the tunnel of the VPN instance, the ingress node adds a new header to the packet. The ingress node sets the TTL value or hop limit in the new header to 255. When the packet leaves the tunnel of the VPN instance, the egress node removes the new header from the packet. The TTL value or hop limit in the original packet does not change when the packet is forwarded in the tunnel. Therefore, the public network nodes are invisible to user networks, and the tracert facility cannot show the real path in the public network.

· Uniform—When an IP or IPv6 packet enters the tunnel of the VPN instance, the ingress node adds a new header to the packet. The ingress node copies the TTL value or the hop limit of the original packet to the TTL or hop limit field of the new header. When the packet leaves the tunnel of the VPN instance, the egress node copies the remaining TTL value or hop limit in the new header back to the original packet. The TTL value or hop limit can reflect how many hops the packet has traversed in the public network. The tracert facility can show the real path along which the packet has traveled.

Restrictions and guidelines

In the current software version, you can configure a TTL processing mode only for SRv6 tunnels associated with VPN instances.

Procedure

1. Enter system view.

system-view

2. Enter VPN instance view.

ip vpn-instance vpn-instance-name

3. Configure a TTL processing mode for the tunnels associated with the VPN instance.

ttl-mode { pipe | uniform }

By default, the TTL processing mode for the tunnels associated with a VPN instance is pipe.

For more information about this command, see MPLS L3VPN configuration in MPLS Configuration Guide.

Display and maintenance commands for IP L3VPN over SRv6

Resetting BGP sessions

For BGP setting changes to take effect, you must reset or soft-reset BGP sessions. Soft-resetting BGP sessions updates BGP routing information without tearing down the BGP sessions. Resetting BGP sessions updates BGP routing information by tearing down and re-establishing the BGP sessions. Soft-reset requires that both the local router and the peer support ROUTE-REFRESH messages.

Execute the commands in this section in user view. For more information about the commands, see BGP in Layer 3—IP Routing Command Reference.

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Task	Command
Soft-reset BGP sessions of the BGP VPNv4 address family.	refresh bgp [ instance instance-name ] ipv6-address [ prefix-length ] { export \| import } vpnv4
Reset BGP sessions of the BGP VPNv4 address family.	reset bgp [ instance instance-name ] ipv6-address [ prefix-length ] vpnv4

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Displaying and maintaining the running status of IP L3VPN over SRv6 VPN

Execute display commands in any view and reset commands in user view.

For more information about the commands in this section, see BGP in Layer 3—IP Routing Command Reference.

Task	Command
Display BGP VPNv4 peer or peer group information.	display bgp [ instance instance-name ] peer vpnv4 { ipv6-address prefix-length \| ipv6-address { log-info \| verbose } }
Display BGP VPNv6 peer or peer group information.	display bgp [ instance instance-name ] peer vpnv6 [ vpn-instance vpn-instance-name ] [ ipv6-address prefix-length \| { ipv6-address \| group-name group-name } log-info \| [ ipv6-address ] verbose ]
Display BGP update group information for VPNv4 address family.	display bgp [ instance instance-name ] update-group vpnv4 ipv6-address
Display BGP update group information for VPNv6 address family.	display bgp [ instance instance-name ] update-group vpnv6 [ vpn-instance vpn-instance-name ] [ ipv6-address ]
Display information about SRv6 SIDs carried in the BGP VPNv4 routes advertised by the local device or received from the peer.	display bgp [ instance instance-name ] routing-table ipv4 [ unicast ] vpn-instance vpn-instance-name { local-sids \| received-sids }
Display information about SRv6 SIDs carried in the BGP VPNv6 routes advertised by the local device or received from the peer.	display bgp [ instance instance-name ] routing-table ipv6 [ unicast ] vpn-instance vpn-instance-name { local-sids \| received-sids }
Clear flap statistics for BGP VPNv4 routes.	reset bgp [ instance instance-name ] flap-info vpnv4 [ ipv4-address [ mask \| mask-length ] \| as-path-acl as-path-acl-number \| peer ipv6-address [ prefix-length ] ]

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IP L3VPN over SRv6 configuration examples

Example: Configuring IP L3VPN over SRv6 BE

Network configuration

As shown in Figure 4, the backbone network is an IPv6 network, and VPN 1 is an IPv4 network. Deploy IP L3VPN over SRv6 between PE 1 and PE 2 and use an SRv6 tunnel to transmit VPNv4 traffic between the PEs.

· Configure EBGP to exchange VPN routing information between the CEs and PEs.

· Configure IPv6 IS-IS on the PEs in the same AS to realize IPv6 network connectivity.

· Configure MP-IBGP to exchange VPNv4 routing information between the PEs.

Figure 4 Network diagram

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Table 1 Interface and IP address assignment

Device	Interface	IP address	Device	Interface	IP address
CE 1	XGE2/0/0	10.1.1.2/24	PE 2	Loop0	3::3/128
PE 1	Loop0	1::1/128		XGE2/0/0	10.2.1.1/24
	XGE2/0/0	10.1.1.1/24		XGE2/0/1	2002::1/96
	XGE2/0/1	2001::1/96	CE 2	XGE2/0/0	10.2.1.2/24
P	Loop0	2::2/128
	XGE2/0/0	2001::2/96
	XGE2/0/1	2002::2/96

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Procedure

1. Configure IPv6 IS-IS on the PEs and device P for network connectivity between the devices:

# Configure PE 1.

<PE1> system-view

[PE1] isis 1

[PE1-isis-1] is-level level-1

[PE1-isis-1] cost-style wide

[PE1-isis-1] network-entity 10.1111.1111.1111.00

[PE1-isis-1] address-family ipv6 unicast

[PE1-isis-1-ipv6] quit

[PE1-isis-1] quit

[PE1] interface loopback 0

[PE1-LoopBack0] ipv6 address 1::1 128

[PE1-LoopBack0] isis ipv6 enable 1

[PE1-LoopBack0] quit

[PE1] interface ten-gigabitethernet 2/0/1

[PE1-Ten-GigabitEthernet2/0/1] ipv6 address 2001::1 96

[PE1-Ten-GigabitEthernet2/0/1] isis ipv6 enable

[PE1-Ten-GigabitEthernet2/0/1] quit

# Configure P.

<P> system-view

[P] isis

[P-isis-1] is-level level-1

[P-isis-1] cost-style wide

[P-isis-1] network-entity 10.2222.2222.2222.00

[P-isis-1] address-family ipv6 unicast

[P-isis-1-ipv6] quit

[P-isis-1] quit

[P] interface loopback 0

[P-LoopBack0] ipv6 address 2::2 128

[P-LoopBack0] isis ipv6 enable

[P-LoopBack0] quit

[P] interface ten-gigabitethernet 2/0/0

[P-Ten-GigabitEthernet2/0/0] ipv6 address 2001::2 96

[P-Ten-GigabitEthernet2/0/0] isis ipv6 enable

[P-Ten-GigabitEthernet2/0/0] quit

[P] interface ten-gigabitethernet 2/0/1

[P-Ten-GigabitEthernet2/0/1] ipv6 address 2002::2 96

[P-Ten-GigabitEthernet2/0/1] isis ipv6 enable

[P-Ten-GigabitEthernet2/0/1] quit

# Configure PE 2.

<PE2> system-view

[PE2] isis

[PE2-isis-1] is-level level-1

[PE2-isis-1] cost-style wide

[PE2-isis-1] network-entity 10.3333.3333.3333.00

[PE2-isis-1] address-family ipv6 unicast

[PE2-isis-1-ipv6] quit

[PE2-isis-1] quit

[PE2] interface loopback 0

[PE2-LoopBack0] ipv6 address 3::3 128

[PE2-LoopBack0] isis ipv6 enable

[PE2-LoopBack0] quit

[PE2] interface ten-gigabitethernet 2/0/1

[PE2-Ten-GigabitEthernet2/0/1] ipv6 address 2002::1 96

[PE2-Ten-GigabitEthernet2/0/1] isis ipv6 enable

[PE2-Ten-GigabitEthernet2/0/1] quit

# Verify that PE 1, P, and PE 2 have established IPv6 IS-IS neighbor relationships and the neighbor state is up with the display isis peer command.

# Verify that PE 1 and PE 2 each learn a route destined for the loopback interface of each other with the display isis route ipv6 command.

2. Configure VPN instance settings on PE 1 and PE 2 and verify that each CE can access its local PE:

# Configure PE 1.

[PE1] ip vpn-instance vpn1

[PE1-vpn-instance-vpn1] route-distinguisher 100:1

[PE1-vpn-instance-vpn1] vpn-target 111:1

[PE1-vpn-instance-vpn1] quit

[PE1] interface ten-gigabitethernet 2/0/0

[PE1-Ten-GigabitEthernet2/0/0] ip binding vpn-instance vpn1

[PE1-Ten-GigabitEthernet2/0/0] ip address 10.1.1.1 24

[PE1-Ten-GigabitEthernet2/0/0] quit

# Configure PE 2.

[PE2] ip vpn-instance vpn1

[PE2-vpn-instance-vpn1] route-distinguisher 100:1

[PE2-vpn-instance-vpn1] vpn-target 111:1

[PE2-vpn-instance-vpn1] quit

[PE2] interface ten-gigabitethernet 2/0/0

[PE2-Ten-GigabitEthernet2/0/0] ip binding vpn-instance vpn1

[PE2-Ten-GigabitEthernet2/0/0] ip address 10.2.1.1 24

[PE2-Ten-GigabitEthernet2/0/0] quit

# Configure IP addresses for the interfaces on the CEs, as shown in Figure 4. (Details not shown.)

# Display VPN instance settings on each PE. This step uses PE 1 as an example.

[PE1] display ip vpn-instance

Total VPN-Instances configured : 1

Total IPv4 VPN-Instances configured : 1

Total IPv6 VPN-Instances configured : 1

VPN-Instance Name RD Address family Create time

vpn1 100:1 N/A 2019/08/12 13:59:39

# Verify that each PE can ping its local CE. This step uses PE 1 and CE 1 as an example.

[PE1] ping -vpn-instance vpn1 10.1.1.2

Ping 10.1.1.2 (10.1.1.2): 56 data bytes, press CTRL+C to break

56 bytes from 10.1.1.2: icmp_seq=0 ttl=255 time=2.000 ms

56 bytes from 10.1.1.2: icmp_seq=1 ttl=255 time=0.000 ms

56 bytes from 10.1.1.2: icmp_seq=2 ttl=255 time=1.000 ms

56 bytes from 10.1.1.2: icmp_seq=3 ttl=255 time=0.000 ms

56 bytes from 10.1.1.2: icmp_seq=4 ttl=255 time=0.000 ms

--- Ping statistics for 10.1.1.2 in VPN instance vpn1 ---

5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss

round-trip min/avg/max/std-dev = 0.000/0.600/2.000/0.800 ms

3. Set up an EBGP peer relationship between each PE and its local CE and distribute VPN routes to EBGP:

# Configure CE 1.

<CE1> system-view

[CE1] bgp 65410

[CE1-bgp-default] peer 10.1.1.1 as-number 100

[CE1-bgp-default] address-family ipv4 unicast

[CE1-bgp-default-ipv4] peer 10.1.1.1 enable

[CE1-bgp-default-ipv4] import-route direct

[CE1-bgp-default-ipv4] quit

[CE1-bgp-default] quit

# Configure CE 2 in the same way as CE 1 is configured. (Details not shown.)

# Configure PE 1.

[PE1] bgp 100

[PE1-bgp-default] router-id 1.1.1.1

[PE1-bgp-default] ip vpn-instance vpn1

[PE1-bgp-default-vpn1] peer 10.1.1.2 as-number 65410

[PE1-bgp-default-vpn1] address-family ipv4 unicast

[PE1-bgp-default-ipv4-vpn1] peer 10.1.1.2 enable

[PE1-bgp-default-ipv4-vpn1] quit

[PE1-bgp-default-vpn1] quit

# Configure PE 2 in the same way PE 1 is configured. (Details not shown.)

# Verify that the PEs have established BGP peer relationships with their local CEs and the peers are in established state with the display bgp peer ipv4 vpn-instance command.

4. Set up an MP-IBGP peer relationship between PE 1 and PE 2:

# Configure PE 1.

[PE1] bgp 100

[PE1-bgp-default] peer 3::3 as-number 100

[PE1-bgp-default] peer 3::3 connect-interface loopback 0

[PE1-bgp-default] address-family vpnv4

[PE1-bgp-default-vpnv4] peer 3::3 enable

[PE1-bgp-default-vpnv4] quit

[PE1-bgp-default] quit

# Configure PE 2.

[PE2] bgp 100

[PE2-bgp-default] peer 1::1 as-number 100

[PE2-bgp-default] peer 1::1 connect-interface loopback 0

[PE2-bgp-default] address-family vpnv4

[PE2-bgp-default-vpnv4] peer 1::1 enable

[PE2-bgp-default-vpnv4] quit

[PE2-bgp-default] quit

# Verify that the PEs have established a BGP peer relationship and the peers are in established state with the display bgp peer vpnv4 command.

5. Specify a source address for the outer IPv6 header of SRv6-encapsulated IP L3VPN packets on PE 1 and PE 2:

# Configure PE 1.

[PE1] segment-routing ipv6

[PE1-segment-routing-ipv6] encapsulation source-address 1::1

# Configure PE 2.

[PE2] segment-routing ipv6

[PE2-segment-routing-ipv6] encapsulation source-address 3::3

6. Configure SRv6 locators on PEs to be advertised through IGP:

# Configure PE 1.

[PE1-segment-routing-ipv6] locator aaa ipv6-prefix 1:2::1:0 96 static 8

[PE1-segment-routing-ipv6-locator-aaa] quit

[PE1-segment-routing-ipv6] quit

[PE1] isis 1

[PE1-isis-1] address-family ipv6 unicast

[PE1-isis-1-ipv6] segment-routing ipv6 locator aaa

[PE1-isis-1-ipv6] quit

[PE1-isis-1] quit

# Configure PE 2.

[PE2-segment-routing-ipv6] locator bbb ipv6-prefix 6:5::1:0 96 static 8

[PE2-segment-routing-ipv6-locator-bbb] quit

[PE2-segment-routing-ipv6] quit

[PE2] isis 1

[PE2-isis-1] address-family ipv6 unicast

[PE2-isis-1-ipv6] segment-routing ipv6 locator bbb

[PE2-isis-1-ipv6] quit

[PE2-isis-1] quit

7. Add End.DT4 SIDs to private network routes on PE 1 and PE 2:

# Configure PE 1.

[PE1] bgp 100

[PE1-bgp-default] ip vpn-instance vpn1

[PE1-bgp-default-vpn1] address-family ipv4 unicast

[PE1-bgp-default-ipv4-vpn1] segment-routing ipv6 locator aaa

[PE1-bgp-default-ipv4-vpn1] quit

[PE1-bgp-default-vpn1] quit

[PE1-bgp-default] quit

# Configure PE 2.

[PE2] bgp 100

[PE2-bgp-default] ip vpn-instance vpn1

[PE2-bgp-default-vpn1] address-family ipv4 unicast

[PE2-bgp-default-ipv4-vpn1] segment-routing ipv6 locator bbb

[PE2-bgp-default-ipv4-vpn1] quit

[PE2-bgp-default-vpn1] quit

[PE2-bgp-default] quit

# Verify that the PEs have distributed the End.DT4 SIDs to the routing table and generated SRv6 routes. This step uses PE 1 as an example.

[PE1] display ipv6 routing-table protocol srv6

Summary count : 1

SRv6 Routing table status : <Active>

Summary count : 1

Destination: 1:2::101/128 Protocol : SRv6

NextHop : ::1 Preference: 4

Interface : InLoop0 Cost : 0

SRv6 Routing table status : <Inactive>

Summary count : 0

8. Enable IPv6 peers on the PEs to exchange End.DT4 SIDs and enable the SID-route-recursion feature:

# Configure PE 1.

[PE1] bgp 100

[PE1-bgp-default] address-family vpnv4

[PE1-bgp-default-vpnv4] peer 3::3 prefix-sid

[PE1-bgp-default-vpnv4] quit

[PE1-bgp-default] ip vpn-instance vpn1

[PE1-bgp-default-vpn1] address-family ipv4 unicast

[PE1-bgp-default-ipv4-vpn1] segment-routing ipv6 best-effort

[PE1-bgp-default-ipv4-vpn1] quit

[PE1-bgp-default-vpn1] quit

[PE1-bgp-default] quit

# Configure PE 2.

[PE2] bgp 100

[PE2-bgp-default] address-family vpnv4

[PE2-bgp-default-vpnv4] peer 1::1 prefix-sid

[PE2-bgp-default-vpnv4] quit

[PE2-bgp-default] ip vpn-instance vpn1

[PE2-bgp-default-vpn1] address-family ipv4 unicast

[PE2-bgp-default-ipv4-vpn1] segment-routing ipv6 best-effort

[PE2-bgp-default-ipv4-vpn1] quit

[PE2-bgp-default-vpn1] quit

[PE2-bgp-default] quit

# Display BGP VPNv4 routing information on each PE and verify that the routes advertised by the PEs have the SID attribute. This step uses PE 1 as an example.

[PE1] display bgp routing-table vpnv4 10.2.1.0

BGP local router ID: 1.1.1.1

Local AS number: 100

Route distinguisher: 100:1(vpn1)

Total number of routes: 1

Paths: 1 available, 1 best

BGP routing table information of 10.2.1.0/24:

From : 3::3 (3.3.3.3)

Rely nexthop : FE80::2A96:34FF:FE9D:216

Original nexthop: 3::3

Out interface : Ten-GigabitEthernet2/0/1

Route age : 00h14m23s

OutLabel : 3

Ext-Community : <RT: 111:1>

RxPathID : 0x0

TxPathID : 0x0

PrefixSID : End.DT4 SID <6:5::101>

…

Verifying the configuration

# Display IPv4 routing table information on the PEs and verify that each PE has a route destined for the remote CE and the next hop of the route is locator of the End.DT4 SID. This step uses PE 1 as an example.

[PE1] display ip routing-table vpn-instance vpn1

Destinations : 11 Routes : 11

Destination/Mask Proto Pre Cost NextHop Interface

0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

10.1.1.0/24 Direct 0 0 10.1.1.1 XGE2/0/0

10.1.1.0/32 Direct 0 0 10.1.1.1 XGE2/0/0

10.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0

10.1.1.255/32 Direct 0 0 10.1.1.1 XGE2/0/0

10.2.1.0/24 BGP 255 0 6:5:: XGE2/0/1

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0

127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0

127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

# Verify that CE 1 and CE 2 can ping each other. (Details not shown.)

Example: Configuring IPv4 L3VPN over G-SRv6 (with COC32 locators)

Network configuration

As shown in Figure 6, the backbone network is an IPv6 network, and VPN aaa is an IPv4 network. Deploy an SRv6 TE policy tunnel between PE 1 and PE 2 in the IPv6 network and use the SRv6 TE policy tunnel to transmit end-to-end VPN traffic.

· Because a large number of devices exist in the backbone network, the SID list for the optimal candidate path of the SRv6 TE policy contains many SRv6 SIDs. To reduce the SRH length for packets, use the G-SRv6 compression solution.

· The SRv6 nodes in the backbone network use COC32 locators, and assign SIDs with the COC flag from the COC32 locators.

· As shown in Figure 5, to prevent packet forwarding issues, appropriately plan the common prefix for the locators in the AS. Specify the common prefix as A:1:1:A:: with 64-bit length for COC32 locators on all devices. In addition, specify the IPv6 address prefix length for the locators as 80 bits, the static portion length for COC32 locators as 8 bits, and the Args portion length as 16 bits. Through calculation, the dynamic portion length in COC32 locators is 8 bits, and the MBZ length is 16 bits.

Figure 5 COC32 locator plan in the AS

Figure 6 Network diagram

‌

Device	Interfaces	IP address	Device	Interfaces	IP address
CE 1	XGE2/0/0	10.1.1.1/30	CE 2	XGE2/0/1	20.1.1.1/30
	Loop0	11.11.11.11/32		Loop0	22.22.22.22/32
PE 1	Loop0	1::1/128	PE 2	Loop0	5::5/128
	XGE2/0/0	10.1.1.2/30		XGE2/0/1	20.1.1.2/30
	XGE2/0/1	12:1:1::1/126		XGE2/0/0	45:1:1::2/126
P 1	Loop0	2::2/128	P 2	Loop0	3::3/128
	XGE2/0/0	23:1:1::1/126		XGE2/0/0	23:1:1::2/126
	XGE2/0/1	12:1:1::2/126		XGE2/0/1	34:1:1::1/126
P 3	Loop0	4::4/128
	XGE2/0/0	45:1:1::1/126
	XGE2/0/1	34:1:1::2/126

‌

Procedure

1. Configure CE 1:

# Configure IP addresses for the interfaces.

<CE1> system-view

[CE1] sysname CE1

[CE1] interface ten-gigabitethernet 2/0/0

[CE1-Ten-GigabitEthernet2/0/0] ip address 10.1.1.1 30

[CE1-Ten-GigabitEthernet2/0/0] quit

[CE1] interface loopback 0

[CE1-LoopBack0] ip address 11.11.11.11 32

[CE1-LoopBack0] quit

# Create EBGP peers between the PE and CE, and import direct routes.

[CE1] bgp 10

[CE1-bgp-default] router-id 11.11.11.11

[CE1-bgp-default] peer 10.1.1.2 as-number 100

[CE1-bgp-default] address-family ipv4 unicast

[CE1-bgp-default-ipv4] peer 10.1.1.2 enable

[CE1-bgp-default-ipv4] import-route direct

[CE1-bgp-default-ipv4] quit

[CE1-bgp-default] quit

2. Configure CE 2:

# Configure IP addresses for the interfaces.

<CE2> system-view

[CE2] sysname CE2

[CE2] interface ten-gigabitethernet 2/0/1

[CE2-Ten-GigabitEthernet2/0/1] ip address 20.1.1.1 30

[CE2-Ten-GigabitEthernet2/0/1] quit

[CE2] interface loopback 0

[CE2-LoopBack0] ip address 22.22.22.22 32

[CE2-LoopBack0] quit

# Create EBGP peers between the PE and CE, and import direct routes.

[CE2] bgp 20

[CE2-bgp-default] router-id 22.22.22.22

[CE2-bgp-default] peer 20.1.1.2 as-number 100

[CE2-bgp-default] address-family ipv4 unicast

[CE2-bgp-default-ipv4] peer 20.1.1.2 enable

[CE2-bgp-default-ipv4] import-route direct

[CE2-bgp-default-ipv4] quit

[CE2-bgp-default] quit

3. Configure PE 1:

# Configure the VPN instance on PE 1 to connect the CE to PE.

<PE1> system-view

[PE1] sysname PE1

[PE1] ip vpn-instance aaa

[PE1-vpn-instance-aaa] route-distinguisher 100:1

[PE1-vpn-instance-aaa] vpn-target 200:1 both

[PE1-vpn-instance-aaa] quit

# Configure IP addresses for the interfaces.

[PE1] interface loopback 0

[PE1-LoopBack0] ipv6 address 1::1 128

[PE1-LoopBack0] quit

[PE1] interface ten-gigabitethernet 2/0/0

[PE1-Ten-GigabitEthernet2/0/0] ip binding vpn-instance aaa

[PE1-Ten-GigabitEthernet2/0/0] ip address 10.1.1.2 30

[PE1-Ten-GigabitEthernet2/0/0] quit

[PE1] interface ten-gigabitethernet 2/0/1

[PE1-Ten-GigabitEthernet2/0/1] ipv6 address 12:1:1::1 126

[PE1-Ten-GigabitEthernet2/0/1] quit

# Configure IPv6 IS-IS to implement backbone network intercommunication.

[PE1] isis 1

[PE1-isis-1] is-level level-2

[PE1-isis-1] cost-style wide

[PE1-isis-1] network-entity 00.0000.0000.0001.00

[PE1-isis-1] address-family ipv6 unicast

[PE1-isis-1-ipv6] quit

[PE1-isis-1] quit

[PE1] interface ten-gigabitethernet 2/0/1

[PE1-Ten-GigabitEthernet2/0/1] isis ipv6 enable 1

[PE1-Ten-GigabitEthernet2/0/1] quit

[PE1] interface loopback 0

[PE1-LoopBack0] isis ipv6 enable 1

[PE1-LoopBack0] quit

# Configure an SRv6 locator on the PE to be advertised by IGP, and enable SRv6 compression.

[PE1] segment-routing-ipv6

[PE1-segment-routing-ipv6] srv6 compress enable

[PE1-segment-routing-ipv6] locator a ipv6-prefix A:1:1:A:1:: 80 common-prefix 64 coc32 static 8 args 16

[PE1-segment-routing-ipv6-locator-a] quit

[PE1-segment-routing-ipv6] quit

[PE1] isis 1

[PE1-isis-1] address-family ipv6 unicast

[PE1-isis-1-ipv6] segment-routing ipv6 locator a auto-sid-coc32

[PE1-isis-1-ipv6] srv6 compress enable

[PE1-isis-1-ipv6] quit

[PE1-isis-1] quit

# Specify a source address for the outer IPv6 header of SRv6-encapsulated IP L3VPN packets on the PE.

[PE1] segment-routing ipv6

[PE1-segment-routing-ipv6] encapsulation source-address 1::1

# Configure the source address of SBFD packets on PE 1.

[PE1] sbfd source-ipv6 1::1

# Configure a static SID list on the PE that contains SRv6 SIDs with the COC flag, specify the static SID list for an SRv6 TE policy, and enable SBFD for the SRv6 TE policy, ensuring that the SRv6 TE policy tunnel can forward services correctly.

In the static SID list:

¡ The first hop is the End.X(COC32) SID of the link from P 1 to P 2. The SRv6 SID in the encapsulated SRH is still 128 bits long without being compressed. The next SID will be compressed.

¡ The second hop is the End(COC32) SID of P 2. The SRv6 SID in the encapsulated SRH is compressed to 32 bits long.

¡ The third hop is the End.X(COC32) SID of the link from P 3 to PE 2. The SRv6 SID in the encapsulated SRH is compressed to 32 bits long.

¡ The fourth hop is the End SID of PE 2. The SRv6 SID in the encapsulated SRH is compressed to 32 bits long. The next SID will not be compressed.

[PE1] segment-routing ipv6

[PE1-segment-routing-ipv6] traffic-engineering

[PE1-srv6-te] srv6-policy locator a

[PE1-srv6-te] segment-list a

[PE1-srv6-te-sl-a] index 10 coc32 ipv6 A:1:1:A:2:20:: 64

[PE1-srv6-te-sl-a] index 20 coc32 ipv6 A:1:1:A:3:10:: 64

[PE1-srv6-te-sl-a] index 30 coc32 ipv6 A:1:1:A:4:20:: 64

[PE1-srv6-te-sl-a] index 40 ipv6 A:1:1:A:5:10::

[PE1-srv6-te-sl-a] quit

[PE1-srv6-te] policy a

[PE1-srv6-te-policy-a] color 10 end-point ipv6 5::5

[PE1-srv6-te-policy-a] sbfd enable remote 1000001

[PE1-srv6-te-policy-a] candidate-paths

[PE1-srv6-te-policy-a-path] preference 200

[PE1-srv6-te-policy-a-path-pref-200] explicit segment-list a

[PE1-srv6-te-policy-a-path-pref-200] quit

[PE1-srv6-te-policy-a-path] quit

[PE1-srv6-te-policy-a] quit

[PE1-srv6-te] quit

[PE1-segment-routing-ipv6] quit

# Create EBGP peers between the PE and CE, and import VPN routes.

[PE1] bgp 100

[PE1-bgp-default] router-id 1.1.1.1

[PE1-bgp-default] ip vpn-instance aaa

[PE1-bgp-default-aaa] peer 10.1.1.1 as-number 10

[PE1-bgp-default-aaa] address-family ipv4 unicast

[PE1-bgp-default-ipv4-aaa] peer 10.1.1.1 enable

[PE1-bgp-default-ipv4-aaa] quit

[PE1-bgp-default-aaa] quit

# Create MP-IBGP peers between PE 1 and PE 2.

[PE1-bgp-default] peer 5::5 as-number 100

[PE1-bgp-default] peer 5::5 connect-interface loopback 0

[PE1-bgp-default] address-family vpnv4

[PE1-bgp-default-vpnv4] peer 5::5 enable

[PE1-bgp-default-vpnv4] quit

[PE1-bgp-default] quit

# Enable exchange of End.DT4 SIDs between IPv6 peers on PE 1, and enable recursion of VPN routes to the SRv6 TE policy tunnel.

[PE1] bgp 100

[PE1-bgp-default] address-family vpnv4

[PE1-bgp-default-vpnv4] peer 5::5 prefix-sid

[PE1-bgp-default-vpnv4] quit

[PE1-bgp-default] ip vpn-instance aaa

[PE1-bgp-default-aaa] address-family ipv4 unicast

[PE1-bgp-default-ipv4-aaa] segment-routing ipv6 locator a

[PE1-bgp-default-ipv4-aaa] segment-routing ipv6 traffic-engineering

[PE1-bgp-default-ipv4-aaa] quit

[PE1-bgp-default-aaa] quit

[PE1-bgp-default] quit

# Configure a routing policy and a tunnel policy on PE 1 to steer VPN service traffic to the specified SRv6 TE policy through the routing policy and ensure that the SRv6 TE policy is the optimal tunnel.

[PE1] route-policy a permit node 10

[PE1-route-policy-a-10] apply extcommunity color 00:10

[PE1-route-policy-a-10] quit

[PE1] bgp 100

[PE1-bgp-default] address-family vpnv4

[PE1-bgp-default-vpnv4] peer 5::5 route-policy a import

[PE1-bgp-default-vpnv4] quit

[PE1-bgp-default] quit

[PE1] tunnel-policy a

[PE1-tunnel-policy-a] select-seq srv6-policy load-balance-number 1

[PE1-tunnel-policy-a] quit

[PE1] ip vpn-instance vpn1

[PE1-vpn-instance-vpn1] tnl-policy a

[PE1-vpn-instance-vpn1] quit

4. Configure P 1:

# Configure IP addresses for the interfaces.

[P1] interface loopback 0

[P1-LoopBack0] ipv6 address 2::2 128

[P1-LoopBack0] quit

[P1] interface ten-gigabitethernet 2/0/0

[P1-Ten-GigabitEthernet2/0/0] ipv6 address 23:1:1::1 126

[P1-Ten-GigabitEthernet2/0/0] quit

[P1] interface ten-gigabitethernet 2/0/1

[P1-Ten-GigabitEthernet2/0/1] ipv6 address 12:1:1::2 126

[P1-Ten-GigabitEthernet2/0/1] quit

# Configure IPv6 IS-IS to implement backbone network intercommunication.

[P1] isis 1

[P1-isis-1] is-level level-2

[P1-isis-1] cost-style wide

[P1-isis-1] network-entity 00.0000.0000.0002.00

[P1-isis-1] address-family ipv6 unicast

[P1-isis-1-ipv6] quit

[P1-isis-1] quit

[P1] interface ten-gigabitethernet 2/0/0

[P1-Ten-GigabitEthernet2/0/0] isis ipv6 enable 1

[P1-Ten-GigabitEthernet2/0/0] quit

[P1] interface ten-gigabitethernet 2/0/1

[P1-Ten-GigabitEthernet2/0/1] isis ipv6 enable 1

[P1-Ten-GigabitEthernet2/0/1] quit

[P1] interface loopback 0

[P1-LoopBack0] isis ipv6 enable 1

[P1-LoopBack0] quit

# Configure an SRv6 locator on P 1 to be advertised by IGP, and enable SRv6 compression.

[P1] segment-routing-ipv6

[P1-segment-routing-ipv6] srv6 compress enable

[P1-segment-routing-ipv6] locator b ipv6-prefix A:1:1:A:2:: 80 common-prefix 64 coc32 static 8 args 16

[P1-segment-routing-ipv6-locator-b] opcode 32 end-x-coc32 interface Ten-GigabitEthernet2/0/0 nexthop 23:1:1::2

[P1-segment-routing-ipv6-locator-b] quit

[P1-segment-routing-ipv6] quit

[P1] isis 1

[P1-isis-1] address-family ipv6 unicast

[P1-isis-1-ipv6] segment-routing ipv6 locator b auto-sid-coc32

[P1-isis-1-ipv6] srv6 compress enable

[P1-isis-1-ipv6] quit

[P1-isis-1] quit

5. Configure P 2:

# Configure IP addresses for the interfaces.

[P2] interface loopback 0

[P2-LoopBack0] ipv6 address 3::3 128

[P2-LoopBack0] quit

[P2] interface ten-gigabitethernet 2/0/0

[P2-Ten-GigabitEthernet2/0/0] ipv6 address 23:1:1::2 126

[P2-Ten-GigabitEthernet2/0/0] quit

[P2] interface ten-gigabitethernet 2/0/1

[P2-Ten-GigabitEthernet2/0/1] ipv6 address 34:1:1::1 126

[P2-Ten-GigabitEthernet2/0/1] quit

# Configure IPv6 IS-IS to implement backbone network intercommunication.

[P2] isis 1

[P2-isis-1] is-level level-2

[P2-isis-1] cost-style wide

[P2-isis-1] network-entity 00.0000.0000.0003.00

[P2-isis-1] address-family ipv6 unicast

[P2-isis-1-ipv6] quit

[P2-isis-1] quit

[P2] interface ten-gigabitethernet 2/0/0

[P2-Ten-GigabitEthernet2/0/0] isis ipv6 enable 1

[P2-Ten-GigabitEthernet2/0/0] quit

[P2] interface ten-gigabitethernet 2/0/1

[P2-Ten-GigabitEthernet2/0/1] isis ipv6 enable 1

[P2-Ten-GigabitEthernet2/0/1] quit

[P2] interface loopback 0

[P2-LoopBack0] isis ipv6 enable 1

[P2-LoopBack0] quit

# Configure an SRv6 locator on P 2 to be advertised by IGP, and enable SRv6 compression.

[P2] segment-routing-ipv6

[P2-segment-routing-ipv6] srv6 compress enable

[P2-segment-routing-ipv6] locator c ipv6-prefix A:1:1:A:3:: 80 common-prefix 64 coc32 static 8 args 16

[P2-segment-routing-ipv6-locator-c] opcode 16 end-coc32

[P2-segment-routing-ipv6-locator-c] quit

[P2-segment-routing-ipv6] quit

[P2] isis 1

[P2-isis-1] address-family ipv6 unicast

[P2-isis-1-ipv6] segment-routing ipv6 locator c auto-sid-coc32

[P2-isis-1-ipv6] srv6 compress enable

[P2-isis-1-ipv6] quit

[P2-isis-1] quit

6. Configure P 3:

# Configure IP addresses for the interfaces.

[P3] interface loopback 0

[P3-LoopBack0] ipv6 address 4::4 128

[P3-LoopBack0] quit

[P3] interface ten-gigabitethernet 2/0/0

[P3-Ten-GigabitEthernet2/0/0] ipv6 address 45:1:1::1 126

[P3-Ten-GigabitEthernet2/0/0] quit

[P3] interface ten-gigabitethernet 2/0/1

[P3-Ten-GigabitEthernet2/0/1] ipv6 address 34:1:1::2 126

[P3-Ten-GigabitEthernet2/0/1] quit

# Configure IPv6 IS-IS to implement backbone network intercommunication.

[P3] isis 1

[P3-isis-1] is-level level-2

[P3-isis-1] cost-style wide

[P3-isis-1] network-entity 00.0000.0000.0004.00

[P3-isis-1] address-family ipv6 unicast

[P3-isis-1-ipv6] quit

[P3-isis-1] quit

[P3] interface ten-gigabitethernet 2/0/0

[P3-Ten-GigabitEthernet2/0/0] isis ipv6 enable 1

[P3-Ten-GigabitEthernet2/0/0] quit

[P3] interface ten-gigabitethernet 2/0/1

[P3-Ten-GigabitEthernet2/0/1] isis ipv6 enable 1

[P3-Ten-GigabitEthernet2/0/1] quit

[P3] interface loopback 0

[P3-LoopBack0] isis ipv6 enable 1

[P3-LoopBack0] quit

# Configure an SRv6 locator on P 3 to be advertised by IGP, and enable SRv6 compression.

[P3] segment-routing-ipv6

[P3-segment-routing-ipv6] srv6 compress enable

[P3-segment-routing-ipv6] locator d ipv6-prefix A:1:1:A:4:: 80 common-prefix 64 coc32 static 8 args 16

[P3-segment-routing-ipv6-locator-d] opcode 32 end-x-coc32 interface Ten-GigabitEthernet2/0/0 nexthop 45:1:1::2

[P3-segment-routing-ipv6-locator-d] quit

[P3-segment-routing-ipv6] quit

[P3] isis 1

[P3-isis-1] address-family ipv6 unicast

[P3-isis-1-ipv6] segment-routing ipv6 locator d auto-sid-coc32

[P3-isis-1-ipv6] srv6 compress enable

[P3-isis-1-ipv6] quit

[P3-isis-1] quit

7. Configure PE 2:

# Configure the VPN instance on PE 2 to connect the CE to PE.

<PE2> system-view

[PE2] sysname PE2

[PE2] ip vpn-instance aaa

[PE2-vpn-instance-aaa] route-distinguisher 100:1

[PE2-vpn-instance-aaa] vpn-target 200:1 both

[PE2-vpn-instance-aaa] quit

# Configure IP addresses for the interfaces.

[PE2] interface loopback 0

[PE2-LoopBack0] ipv6 address 5::5 128

[PE2-LoopBack0] quit

[PE2] interface ten-gigabitethernet 2/0/1

[PE2-Ten-GigabitEthernet2/0/1] ip binding vpn-instance aaa

[PE2-Ten-GigabitEthernet2/0/1] ip address 20.1.1.2 30

[PE2-Ten-GigabitEthernet2/0/1] quit

[PE2] interface ten-gigabitethernet 2/0/0

[PE2-Ten-GigabitEthernet2/0/0] ipv6 address 45:1:1::2 126

[PE2-Ten-GigabitEthernet2/0/0] quit

# Configure IPv6 IS-IS to implement backbone network intercommunication.

[PE2] isis 1

[PE2-isis-1] is-level level-2

[PE2-isis-1] cost-style wide

[PE2-isis-1] network-entity 00.0000.0000.0005.00

[PE2-isis-1] address-family ipv6 unicast

[PE2-isis-1-ipv6] quit

[PE2-isis-1] quit

[PE2] interface ten-gigabitethernet 2/0/0

[PE2-Ten-GigabitEthernet2/0/0] isis ipv6 enable 1

[PE2-Ten-GigabitEthernet2/0/0] quit

[PE2] interface loopback 0

[PE2-LoopBack0] isis ipv6 enable 1

[PE2-LoopBack0] quit

# Configure an SRv6 locator on the PE to be advertised by IGP, and enable SRv6 compression.

[PE2] segment-routing-ipv6

[PE2-segment-routing-ipv6] srv6 compress enable

[PE2-segment-routing-ipv6] locator e ipv6-prefix A:1:1:A:5:: 80 common-prefix 64 coc32 static 8 args 16

[PE2-segment-routing-ipv6-locator-e] opcode 16 end

[PE2-segment-routing-ipv6-locator-e] quit

[PE2-segment-routing-ipv6] quit

[PE2] isis 1

[PE2-isis-1] address-family ipv6 unicast

[PE2-isis-1-ipv6] segment-routing ipv6 locator e auto-sid-coc32

[PE2-isis-1-ipv6] srv6 compress enable

[PE2-isis-1-ipv6] quit

[PE2-isis-1] quit

# Specify a source address for the outer IPv6 header of SRv6-encapsulated IP L3VPN packets on the PE.

[PE2] segment-routing ipv6

[PE2-segment-routing-ipv6] encapsulation source-address 5::5

# Create EBGP peers between the PE and CE, and import VPN routes.

[PE2] bgp 100

[PE2-bgp-default] router-id 5.5.5.5

[PE2-bgp-default] ip vpn-instance aaa

[PE2-bgp-default-aaa] peer 20.1.1.1 as-number 20

[PE2-bgp-default-aaa] address-family ipv4 unicast

[PE2-bgp-default-ipv4-aaa] peer 20.1.1.1 enable

[PE2-bgp-default-ipv4-aaa] quit

[PE2-bgp-default-aaa] quit

# Create MP-IBGP peers between PE 1 and PE 2.

[PE2-bgp-default] peer 1::1 as-number 100

[PE2-bgp-default] peer 1::1 connect-interface loopback 0

[PE2-bgp-default] address-family vpnv4

[PE2-bgp-default-vpnv4] peer 1::1 enable

[PE2-bgp-default-vpnv4] quit

[PE2-bgp-default] quit

# Enable exchange of End.DT4 SIDs between IPv6 peers on PE 2, and enable recursion of VPN routes to the SRv6 BE tunnel.

[PE2] bgp 100

[PE2-bgp-default] address-family vpnv4

[PE2-bgp-default-vpnv4] peer 1::1 prefix-sid

[PE2-bgp-default-vpnv4] quit

[PE2-bgp-default] ip vpn-instance aaa

[PE2-bgp-default-aaa] address-family ipv4 unicast

[PE2-bgp-default-ipv4-aaa] segment-routing ipv6 locator e

[PE2-bgp-default-ipv4-aaa] segment-routing ipv6 best-effort

[PE2-bgp-default-ipv4-aaa] quit

[PE2-bgp-default-aaa] quit

[PE2-bgp-default] quit

# Specify the local discriminator for the SBFD session on PE 2, and make sure it is the same as the remote discriminator on PE 1.

[PE2] sbfd local-discriminator 1000001

Verifying the configuration

# On PE 1, execute the display segment-routing ipv6 te policy command to display detailed SRv6 TE policy information. Verify that the Status field for the SRv6 TE policy is Up, and the SID list state is Up.

<PE1> display segment-routing ipv6 te policy

Name/ID: a/0

Color: 10

End-point: 5::5

Name from BGP:

Name from PCE:

BSID:

Mode: Dynamic Type: Type_2 Request state: Succeeded

Current BSID: A:1:1:A:1:104:: Explicit BSID: - Dynamic BSID: A:1:1:A:1:104::

Reference counts: 5

Flags: A/BS/NC

Status: Up

AdminStatus: Up

Up time: 2023-08-04 16:21:25

Down time: 2023-08-04 16:13:02

Hot backup: Disabled

Statistics: Disabled

Statistics by service class: Disabled

Path verification: Not configured

Drop-upon-invalid: Disabled

BFD trigger path-down: Disabled

SBFD: Enabled

Encapsulation mode: -

Remote: 1000001

SBFD template name: -

SBFD backup template name: -

OAM SID: -

Reverse path type: None

BFD Echo: Disabled

Forwarding index: 2150629377

Association ID: 0

Service-class: -

Rate-limit: -

PCE delegation: Disabled

PCE delegate report-only: Disabled

Reoptimization: Disabled

Encapsulation mode: -

Flapping suppression Remaining interval: -

Candidate paths state: Configured

Candidate paths statistics:

CLI paths: 1 BGP paths: 0 PCEP paths: 0 ODN paths: 0

Candidate paths:

Preference : 200

Network slice ID: -

CPathName:

CPathPolicyName:

ProtoOrigin: CLI Discriminator: 200

Instance ID: 0 Node address: 0.0.0.0

Originator: 0, ::

Optimal: Y Flags: V/A

Dynamic: Not configured

PCEP: Not configured

Explicit SID list:

ID: 1 Name: a

Weight: 1 Forwarding index: 2149580802

State: Up State(SBFD): Up

Verification State: -

Path MTU: 1500 Path MTU Reserved: 0

SID list flags: None

Local BSID: -

Reverse BSID: -

# On PE 1, execute the display bgp routing-table vpnv4 command to display detailed information about the route sent by PE 2. Verify that the route sent by PE 2 carries the PrefixSID attribute data, and the route is recursed to SRv6 TE policy tunnel a.

<PE1> display bgp routing-table vpnv4 22.22.22.22

BGP local router ID: 1.1.1.1

Local AS number: 100

Route distinguisher: 100:1(aaa)

Total number of routes: 1

Paths: 1 available, 1 best

BGP routing table information of 22.22.22.22/32:

From : 5::5 (5.5.5.5)

Rely nexthop : FE80::1AF8:23FF:FE50:207

Original nexthop: 5::5

Out interface : Ten-GigabitEthernet2/0/1

Route age : 03h52m50s

OutLabel : 3

Ext-Community : <RT: 200:1>, <CO-Flag:Color(00:10)>

RxPathID : 0x0

TxPathID : 0x0

PrefixSID : End.DT4 SID <A:1:1:A:5:104::>

SRv6 Service TLV (37 bytes):

Type: SRV6 L3 Service TLV (5)

Length: 34 bytes, Reserved: 0x0

SRv6 Service Information Sub-TLV (33 bytes):

Type: 1 Length: 30, Rsvdl: 0x0

SID Flags: 0x0 Endpoint behavior: 0x13 Rsvd2: 0x0

SRv6 SID Sub-Sub-TLV:

Type: 1 Len: 6

BL: 64 NL: 16 FL: 16 AL: 16 TL: 0 TO: 0

AS-path : 20

Origin : incomplete

Attribute value : MED 0, localpref 100, pref-val 0

State : valid, internal, best

Source type : local

IP precedence : N/A

QoS local ID : N/A

Traffic index : N/A

Tunnel policy : a

Rely tunnel IDs : 2150629377

# On PE 1, execute the display ip routing-table vpn-instance command. Verify that VPN route 22.22.22.22 is available to CE 2, and the output interface for the route is SRv6 TE policy tunnel a.

Take PE 1 as an example:

<PE1> display ip routing-table vpn-instance aaa

Destinations : 8 Routes : 8

Destination/Mask Proto Pre Cost NextHop Interface

10.1.1.0/30 Direct 0 0 10.1.1.2 XGE2/0/0

10.1.1.2/32 Direct 0 0 127.0.0.1 XGE2/0/0

10.1.1.3/32 Direct 0 0 10.1.1.2 XGE2/0/0

11.11.11.11/32 BGP 255 0 10.1.1.1 XGE2/0/0

20.1.1.0/30 BGP 255 0 5::5 a

22.22.22.22/32 BGP 255 0 5::5 a

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

# From source IP address 11.11.11.11 on CE 1, ping destination IP address 22.22.22.22 on CE 2. Verify that the ping operation is successful. Capture packets on the forwarding interfaces of the devices such as PE 1 to verify that the second-, third-, and fourth-hop SIDs are all compressed to 32 bits in the static SID list of the SRH. Compression is implemented through G-SRv6.

Example: Configuring IPv4 L3VPN over G-SRv6 (with COC-both locators)

Network configuration

As shown in Figure 8, the backbone network is an IPv6 network, and VPN aaa is an IPv4 network. Deploy an SRv6 TE policy tunnel between PE 1 and PE 2 in the IPv6 network and use the SRv6 TE policy tunnel to transmit end-to-end VPN traffic.

· The SRv6 nodes in the backbone network use COC-both locators, and dynamically assign various types of SRv6 SIDs from the COC-both locators. Execute the display segment-routing ipv6 local-sid command on each SRv6 node to display local Srv6 SIDs. Add the SRv6 SIDs in the appropriate order to the SID list of the SRv6 TE policy.

· As shown in Figure 7, to prevent packet forwarding issues, appropriately plan the common prefix for the locators in the AS. Specify the common prefix as A:2:2:A:: with 64-bit length for COC-both locators on all devices. In addition, specify the IPv6 address prefix length for the locators as 80 bits, the compressible static portion length (C-SID Static) for COC-both locators as 8 bits, the non-compressible static portion length (NC-SID Static) as 8 bits, and the Args portion length as 16 bits. Through calculation, the compressible dynamic portion length (C-SID Dynamic) is 8 bits, and the non-compressible static portion length (NC-SID Static) is 8 bits.

· In the compressible SID (C-SID) range, you can dynamically assign or statically specify SIDs with the COC flag, for example, End(COC32) SIDs and End.X(COC32) SIDs. You can also dynamically assign or statically specify SIDs without the COC flag, for example, End(COCNONE) SIDs and End.X(COCNONE) SIDs. In the non-compressible SID (NC-SID) range, you can assign common SIDs, for example, End SIDs and End.X SIDs.

Figure 7 COC-both locator plan in the AS

Figure 8 Network diagram

‌

Device	Interfaces	IP address	Device	Interfaces	IP address
CE 1	XGE2/0/0	10.1.1.1/30	CE 2	XGE2/0/1	20.1.1.1/30
	Loop0	11.11.11.11/32		Loop0	22.22.22.22/32
PE 1	Loop0	1::1/128	PE 2	Loop0	5::5/128
	XGE2/0/0	10.1.1.2/30		XGE2/0/1	20.1.1.2/30
	XGE2/0/1	12:1:1::1/126		XGE2/0/0	45:1:1::2/126
P 1	Loop0	2::2/128	P 2	Loop0	3::3/128
	XGE2/0/0	23:1:1::1/126		XGE2/0/0	23:1:1::2/126
	XGE2/0/1	12:1:1::2/126		XGE2/0/1	34:1:1::1/126
P 3	Loop0	4::4/128
	XGE2/0/0	45:1:1::1/126
	XGE2/0/1	34:1:1::2/126

Procedure

1. Configure CE 1:

# Configure IP addresses for the interfaces.

<CE1> system-view

[CE1] sysname CE1

[CE1] interface ten-gigabitethernet 2/0/0

[CE1-Ten-GigabitEthernet2/0/0] ip address 10.1.1.1 30

[CE1-Ten-GigabitEthernet2/0/0] quit

[CE1] interface loopback 0

[CE1-LoopBack0] ip address 11.11.11.11 32

[CE1-LoopBack0] quit

# Create EBGP peers between the PE and CE, and import direct routes.

[CE1] bgp 10

[CE1-bgp-default] router-id 11.11.11.11

[CE1-bgp-default] peer 10.1.1.2 as-number 100

[CE1-bgp-default] address-family ipv4 unicast

[CE1-bgp-default-ipv4] peer 10.1.1.2 enable

[CE1-bgp-default-ipv4] import-route direct

[CE1-bgp-default-ipv4] quit

[CE1-bgp-default] quit

2. Configure CE 2:

# Configure IP addresses for the interfaces.

<CE2> system-view

[CE2] sysname CE2

[CE2] interface ten-gigabitethernet 2/0/1

[CE2-Ten-GigabitEthernet2/0/1] ip address 20.1.1.1 30

[CE2-Ten-GigabitEthernet2/0/1] quit

[CE2] interface loopback 0

[CE2-LoopBack0] ip address 22.22.22.22 32

[CE2-LoopBack0] quit

# Create EBGP peers between the PE and CE, and import direct routes.

[CE2] bgp 20

[CE2-bgp-default] router-id 22.22.22.22

[CE2-bgp-default] peer 20.1.1.2 as-number 100

[CE2-bgp-default] address-family ipv4 unicast

[CE2-bgp-default-ipv4] peer 20.1.1.2 enable

[CE2-bgp-default-ipv4] import-route direct

[CE2-bgp-default-ipv4] quit

[CE2-bgp-default] quit

3. Configure PE 1:

# Configure the VPN instance on PE 1 to connect the CE to PE.

<PE1> system-view

[PE1] sysname PE1

[PE1] ip vpn-instance aaa

[PE1-vpn-instance-aaa] route-distinguisher 100:1

[PE1-vpn-instance-aaa] vpn-target 200:1 both

[PE1-vpn-instance-aaa] quit

# Configure IP addresses for the interfaces.

[PE1] interface loopback 0

[PE1-LoopBack0] ipv6 address 1::1 128

[PE1-LoopBack0] quit

[PE1] interface ten-gigabitethernet 2/0/0

[PE1-Ten-GigabitEthernet2/0/0] ip binding vpn-instance aaa

[PE1-Ten-GigabitEthernet2/0/0] ip address 10.1.1.2 30

[PE1-Ten-GigabitEthernet2/0/0] quit

[PE1] interface ten-gigabitethernet 2/0/1

[PE1-Ten-GigabitEthernet2/0/1] ipv6 address 12:1:1::1 126

[PE1-Ten-GigabitEthernet2/0/1] quit

# Configure IPv6 IS-IS to implement backbone network intercommunication.

[PE1] isis 1

[PE1-isis-1] is-level level-2

[PE1-isis-1] cost-style wide

[PE1-isis-1] network-entity 00.0000.0000.0001.00

[PE1-isis-1] address-family ipv6 unicast

[PE1-isis-1-ipv6] quit

[PE1-isis-1] quit

[PE1] interface ten-gigabitethernet 2/0/1

[PE1-Ten-GigabitEthernet2/0/1] isis ipv6 enable 1

[PE1-Ten-GigabitEthernet2/0/1] quit

[PE1] interface loopback 0

[PE1-LoopBack0] isis ipv6 enable 1

[PE1-LoopBack0] quit

# Configure an SRv6 locator on the PE to be advertised by IGP, and enable SRv6 compression.

[PE1] segment-routing-ipv6

[PE1-segment-routing-ipv6] srv6 compress enable

[PE1-segment-routing-ipv6] locator ax ipv6-prefix A:2:2:A:1:: 80 common-prefix 64 coc-both non-compress-static 8 static 8 args 16

[PE1-segment-routing-ipv6-locator-ax] quit

[PE1-segment-routing-ipv6] quit

[PE1] isis 1

[PE1-isis-1] address-family ipv6 unicast

[PE1-isis-1-ipv6] segment-routing ipv6 locator ax auto-sid-coc-both coc32

[PE1-isis-1-ipv6] srv6 compress enable

[PE1-isis-1-ipv6] quit

[PE1-isis-1] quit

# Specify a source address for the outer IPv6 header of SRv6-encapsulated IP L3VPN packets on the PE.

[PE1] segment-routing ipv6

[PE1-segment-routing-ipv6] encapsulation source-address 1::1

# Configure the source address of SBFD packets on PE 1.

[PE1] sbfd source-ipv6 1::1

In the static SID list:

¡ The first hop is the End.X(COC32) SID of the link from P 1 to P 2. The SRv6 SID in the encapsulated SRH is still 128 bits long without being compressed. The next SID will be compressed. After configuring P1, you can execute the display segment-routing ipv6 local-sid command to obtain information about dynamically allocated End.X(COC32) SIDs.

¡ The second hop is the End(COC32) SID of P 2. The SRv6 SID in the encapsulated SRH is compressed to 32 bits long. After configuring P 2, you can execute the display segment-routing ipv6 local-sid command to obtain information about dynamically allocated End(COC32) SIDs.

¡ The third hop is the End.X(COC32) SID of the link from P 3 to PE 2. The SRv6 SID in the encapsulated SRH is compressed to 32 bits long. After configuring P 3, you can execute the display segment-routing ipv6 local-sid command to obtain information about dynamically allocated End.X(COC32) SIDs.

¡ The fourth hop is the End SID of PE 2. The SRv6 SID in the encapsulated SRH is compressed to 32 bits long. The next SID will not be compressed. After configuring PE 2, you can execute the display segment-routing ipv6 local-sid command to obtain information about dynamically allocated End(COCNONE) SIDs.

[PE1] segment-routing ipv6

[PE1-segment-routing-ipv6] traffic-engineering

[PE1-srv6-te] srv6-policy locator ax

[PE1-srv6-te] segment-list b

[PE1-srv6-te-sl-b] index 10 coc32 ipv6 A:2:2:A:2:10A:: 64

[PE1-srv6-te-sl-b] index 20 coc32 ipv6 A:2:2:A:3:101:: 64

[PE1-srv6-te-sl-b] index 30 coc32 ipv6 A:2:2:A:4:104:: 64

[PE1-srv6-te-sl-b] index 40 ipv6 A:2:2:A:5:103::

[PE1-srv6-te-sl-b] quit

[PE1-srv6-te] policy a

[PE1-srv6-te-policy-a] color 10 end-point ipv6 5::5

[PE1-srv6-te-policy-a] sbfd enable remote 1000001

[PE1-srv6-te-policy-a] candidate-paths

[PE1-srv6-te-policy-a-path] preference 200

[PE1-srv6-te-policy-a-path-pref-200] explicit segment-list b

[PE1-srv6-te-policy-a-path-pref-200] quit

[PE1-srv6-te-policy-a-path] quit

[PE1-srv6-te-policy-a] quit

[PE1-srv6-te] quit

[PE1-segment-routing-ipv6] quit

# Create EBGP peers between the PE and CE, and import VPN routes.

[PE1] bgp 100

[PE1-bgp-default] router-id 1.1.1.1

[PE1-bgp-default] ip vpn-instance aaa

[PE1-bgp-default-aaa] peer 10.1.1.1 as-number 10

[PE1-bgp-default-aaa] address-family ipv4 unicast

[PE1-bgp-default-ipv4-aaa] peer 10.1.1.1 enable

[PE1-bgp-default-ipv4-aaa] quit

[PE1-bgp-default-aaa] quit

# Create MP-IBGP peers between PE 1 and PE 2.

[PE1-bgp-default] peer 5::5 as-number 100

[PE1-bgp-default] peer 5::5 connect-interface loopback 0

[PE1-bgp-default] address-family vpnv4

[PE1-bgp-default-vpnv4] peer 5::5 enable

[PE1-bgp-default-vpnv4] quit

[PE1-bgp-default] quit

# Enable exchange of End.DT4 SIDs between IPv6 peers on PE 1, and enable recursion of VPN routes to the SRv6 TE policy tunnel.

[PE1] bgp 100

[PE1-bgp-default] address-family vpnv4

[PE1-bgp-default-vpnv4] peer 5::5 prefix-sid

[PE1-bgp-default-vpnv4] quit

[PE1-bgp-default] ip vpn-instance aaa

[PE1-bgp-default-aaa] address-family ipv4 unicast

[PE1-bgp-default-ipv4-aaa] segment-routing ipv6 locator ax

[PE1-bgp-default-ipv4-aaa] segment-routing ipv6 traffic-engineering

[PE1-bgp-default-ipv4-aaa] quit

[PE1-bgp-default-aaa] quit

[PE1-bgp-default] quit

[PE1] route-policy a permit node 10

[PE1-route-policy-a-10] apply extcommunity color 00:10

[PE1-route-policy-a-10] quit

[PE1] bgp 100

[PE1-bgp-default] address-family vpnv4

[PE1-bgp-default-vpnv4] peer 5::5 route-policy a import

[PE1-bgp-default-vpnv4] quit

[PE1-bgp-default] quit

[PE1] tunnel-policy a

[PE1-tunnel-policy-a] select-seq srv6-policy load-balance-number 1

[PE1-tunnel-policy-a] quit

[PE1] ip vpn-instance vpn1

[PE1-vpn-instance-vpn1] tnl-policy a

[PE1-vpn-instance-vpn1] quit

4. Configure P 1:

# Configure IP addresses for the interfaces.

[P1] interface loopback 0

[P1-LoopBack0] ipv6 address 2::2 128

[P1-LoopBack0] quit

[P1] interface ten-gigabitethernet 2/0/0

[P1-Ten-GigabitEthernet2/0/0] ipv6 address 23:1:1::1 126

[P1-Ten-GigabitEthernet2/0/0] quit

[P1] interface ten-gigabitethernet 2/0/1

[P1-Ten-GigabitEthernet2/0/1] ipv6 address 12:1:1::2 126

[P1-Ten-GigabitEthernet2/0/1] quit

# Configure IPv6 IS-IS to implement backbone network intercommunication.

[P1] isis 1

[P1-isis-1] is-level level-2

[P1-isis-1] cost-style wide

[P1-isis-1] network-entity 00.0000.0000.0002.00

[P1-isis-1] address-family ipv6 unicast

[P1-isis-1-ipv6] quit

[P1-isis-1] quit

[P1] interface ten-gigabitethernet 2/0/0

[P1-Ten-GigabitEthernet2/0/0] isis ipv6 enable 1

[P1-Ten-GigabitEthernet2/0/0] quit

[P1] interface ten-gigabitethernet 2/0/1

[P1-Ten-GigabitEthernet2/0/1] isis ipv6 enable 1

[P1-Ten-GigabitEthernet2/0/1] quit

[P1] interface loopback 0

[P1-LoopBack0] isis ipv6 enable 1

[P1-LoopBack0] quit

# Configure an SRv6 locator on P 1 to be advertised by IGP, and enable SRv6 compression.

[P1] segment-routing-ipv6

[P1-segment-routing-ipv6] srv6 compress enable

[P1-segment-routing-ipv6] locator bx ipv6-prefix A:2:2:A:2:: 80 common-prefix 64 coc-both non-compress-static 8 static 8 args 16

[P1-segment-routing-ipv6-locator-bx] quit

[P1-segment-routing-ipv6] quit

[P1] isis 1

[P1-isis-1] address-family ipv6 unicast

[P1-isis-1-ipv6] segment-routing ipv6 locator bx auto-sid-coc-both coc32-all

[P1-isis-1-ipv6] srv6 compress enable

[P1-isis-1-ipv6] quit

[P1-isis-1] quit

5. Configure P 2:

# Configure IP addresses for the interfaces.

[P2] interface loopback 0

[P2-LoopBack0] ipv6 address 3::3 128

[P2-LoopBack0] quit

[P2] interface ten-gigabitethernet 2/0/0

[P2-Ten-GigabitEthernet2/0/0] ipv6 address 23:1:1::2 126

[P2-Ten-GigabitEthernet2/0/0] quit

[P2] interface ten-gigabitethernet 2/0/1

[P2-Ten-GigabitEthernet2/0/1] ipv6 address 34:1:1::1 126

[P2-Ten-GigabitEthernet2/0/1] quit

# Configure IPv6 IS-IS to implement backbone network intercommunication.

[P2] isis 1

[P2-isis-1] is-level level-2

[P2-isis-1] cost-style wide

[P2-isis-1] network-entity 00.0000.0000.0003.00

[P2-isis-1] address-family ipv6 unicast

[P2-isis-1-ipv6] quit

[P2-isis-1] quit

[P2] interface ten-gigabitethernet 2/0/0

[P2-Ten-GigabitEthernet2/0/0] isis ipv6 enable 1

[P2-Ten-GigabitEthernet2/0/0] quit

[P2] interface ten-gigabitethernet 2/0/1

[P2-Ten-GigabitEthernet2/0/1] isis ipv6 enable 1

[P2-Ten-GigabitEthernet2/0/1] quit

[P2] interface loopback 0

[P2-LoopBack0] isis ipv6 enable 1

[P2-LoopBack0] quit

# Configure an SRv6 locator on P 2 to be advertised by IGP, and enable SRv6 compression.

[P2] segment-routing-ipv6

[P2-segment-routing-ipv6] srv6 compress enable

[P2-segment-routing-ipv6] locator cx ipv6-prefix A:2:2:A:3:: 80 common-prefix 64 coc-both non-compress-static 8 static 8 args 16

[P2-segment-routing-ipv6-locator-cx] quit

[P2-segment-routing-ipv6] quit

[P2] isis 1

[P2-isis-1] address-family ipv6 unicast

[P2-isis-1-ipv6] segment-routing ipv6 locator cx auto-sid-coc-both all

[P2-isis-1-ipv6] srv6 compress enable

[P2-isis-1-ipv6] quit

[P2-isis-1] quit

6. Configure P 3:

# Configure IP addresses for the interfaces.

[P3] interface loopback 0

[P3-LoopBack0] ipv6 address 4::4 128

[P3-LoopBack0] quit

[P3] interface ten-gigabitethernet 2/0/0

[P3-Ten-GigabitEthernet2/0/0] ipv6 address 45:1:1::1 126

[P3-Ten-GigabitEthernet2/0/0] quit

[P3] interface ten-gigabitethernet 2/0/1

[P3-Ten-GigabitEthernet2/0/1] ipv6 address 34:1:1::2 126

[P3-Ten-GigabitEthernet2/0/1] quit

# Configure IPv6 IS-IS to implement backbone network intercommunication.

[P3] isis 1

[P3-isis-1] is-level level-2

[P3-isis-1] cost-style wide

[P3-isis-1] network-entity 00.0000.0000.0004.00

[P3-isis-1] address-family ipv6 unicast

[P3-isis-1-ipv6] quit

[P3-isis-1] quit

[P3] interface ten-gigabitethernet 2/0/0

[P3-Ten-GigabitEthernet2/0/0] isis ipv6 enable 1

[P3-Ten-GigabitEthernet2/0/0] quit

[P3] interface ten-gigabitethernet 2/0/1

[P3-Ten-GigabitEthernet2/0/1] isis ipv6 enable 1

[P3-Ten-GigabitEthernet2/0/1] quit

[P3] interface loopback 0

[P3-LoopBack0] isis ipv6 enable 1

[P3-LoopBack0] quit

# Configure an SRv6 locator on P 3 to be advertised by IGP, and enable SRv6 compression.

[P3] segment-routing-ipv6

[P3-segment-routing-ipv6] srv6 compress enable

[P3-segment-routing-ipv6] locator dx ipv6-prefix A:2:2:A:4:: 80 common-prefix 64 coc-both non-compress-static 8 static 8 args 16

[P3-segment-routing-ipv6-locator-dx] quit

[P3-segment-routing-ipv6] quit

[P3] isis 1

[P3-isis-1] address-family ipv6 unicast

[P3-isis-1-ipv6] segment-routing ipv6 locator dx auto-sid-coc-both coc32

[P3-isis-1-ipv6] srv6 compress enable

[P3-isis-1-ipv6] quit

[P3-isis-1] quit

7. Configure PE 2:

# Configure the VPN instance on PE 2 to connect the CE to PE.

<PE2> system-view

[PE2] sysname PE2

[PE2] ip vpn-instance aaa

[PE2-vpn-instance-aaa] route-distinguisher 100:1

[PE2-vpn-instance-aaa] vpn-target 200:1 both

[PE2-vpn-instance-aaa] quit

# Configure IP addresses for the interfaces.

[PE2] interface loopback 0

[PE2-LoopBack0] ipv6 address 5::5 128

[PE2-LoopBack0] quit

[PE2] interface ten-gigabitethernet 2/0/1

[PE2-Ten-GigabitEthernet2/0/1] ip binding vpn-instance aaa

[PE2-Ten-GigabitEthernet2/0/1] ip address 20.1.1.2 30

[PE2-Ten-GigabitEthernet2/0/1] quit

[PE2] interface ten-gigabitethernet 2/0/0

[PE2-Ten-GigabitEthernet2/0/0] ipv6 address 45:1:1::2 126

[PE2-Ten-GigabitEthernet2/0/0] quit

# Configure IPv6 IS-IS to implement backbone network intercommunication.

[PE2] isis 1

[PE2-isis-1] is-level level-2

[PE2-isis-1] cost-style wide

[PE2-isis-1] network-entity 00.0000.0000.0005.00

[PE2-isis-1] address-family ipv6 unicast

[PE2-isis-1-ipv6] quit

[PE2-isis-1] quit

[PE2] interface ten-gigabitethernet 2/0/0

[PE2-Ten-GigabitEthernet2/0/0] isis ipv6 enable 1

[PE2-Ten-GigabitEthernet2/0/0] quit

[PE2] interface loopback 0

[PE2-LoopBack0] isis ipv6 enable 1

[PE2-LoopBack0] quit

# Configure an SRv6 locator on the PE to be advertised by IGP, and enable SRv6 compression.

[PE2] segment-routing-ipv6

[PE2-segment-routing-ipv6] srv6 compress enable

[PE2-segment-routing-ipv6] locator ex ipv6-prefix A:2:2:A:5:: 80 common-prefix 64 coc-both non-compress-static 8 static 8 args 16

[PE2-segment-routing-ipv6-locator-e] quit

[PE2-segment-routing-ipv6] quit

[PE2] isis 1

[PE2-isis-1] address-family ipv6 unicast

[PE2-isis-1-ipv6] segment-routing ipv6 locator ex auto-sid-coc-both all

[PE2-isis-1-ipv6] srv6 compress enable

[PE2-isis-1-ipv6] quit

[PE2-isis-1] quit

# Specify a source address for the outer IPv6 header of SRv6-encapsulated IP L3VPN packets on the PE.

[PE2] segment-routing ipv6

[PE2-segment-routing-ipv6] encapsulation source-address 5::5

# Create EBGP peers between the PE and CE, and import VPN routes.

[PE2] bgp 100

[PE2-bgp-default] router-id 5.5.5.5

[PE2-bgp-default] ip vpn-instance aaa

[PE2-bgp-default-aaa] peer 20.1.1.1 as-number 20

[PE2-bgp-default-aaa] address-family ipv4 unicast

[PE2-bgp-default-ipv4-aaa] peer 20.1.1.1 enable

[PE2-bgp-default-ipv4-aaa] quit

[PE2-bgp-default-aaa] quit

# Create MP-IBGP peers between PE 1 and PE 2.

[PE2-bgp-default] peer 1::1 as-number 100

[PE2-bgp-default] peer 1::1 connect-interface loopback 0

[PE2-bgp-default] address-family vpnv4

[PE2-bgp-default-vpnv4] peer 1::1 enable

[PE2-bgp-default-vpnv4] quit

[PE2-bgp-default] quit

# Enable exchange of End.DT4 SIDs between IPv6 peers on PE 2, and enable recursion of VPN routes to the SRv6 BE tunnel.

[PE2] bgp 100

[PE2-bgp-default] address-family vpnv4

[PE2-bgp-default-vpnv4] peer 1::1 prefix-sid

[PE2-bgp-default-vpnv4] quit

[PE2-bgp-default] ip vpn-instance aaa

[PE2-bgp-default-aaa] address-family ipv4 unicast

[PE2-bgp-default-ipv4-aaa] segment-routing ipv6 locator ex

[PE2-bgp-default-ipv4-aaa] segment-routing ipv6 best-effort

[PE2-bgp-default-ipv4-aaa] quit

[PE2-bgp-default-aaa] quit

[PE2-bgp-default] quit

# Specify the local discriminator for the SBFD session on PE 2, and make sure it is the same as the remote discriminator on PE 1.

[PE2] sbfd local-discriminator 1000001

Verifying the configuration

<PE1> display segment-routing ipv6 te policy

Name/ID: a/0

Color: 10

End-point: 5::5

Name from BGP:

Name from PCE:

BSID:

Mode: Dynamic Type: Type_2 Request state: Succeeded

Current BSID: A:2:2:A:1:0:101:0 Explicit BSID: - Dynamic BSID: A:2:2:A:1:0:101:0

Reference counts: 5

Flags: A/BS/NC

Status: Up

AdminStatus: Up

Up time: 2023-08-06 16:31:34

Down time: 2023-08-06 16:29:20

Hot backup: Disabled

Statistics: Disabled

Statistics by service class: Disabled

Path verification: Not configured

Drop-upon-invalid: Disabled

BFD trigger path-down: Disabled

SBFD: Enabled

Encapsulation mode: -

Remote: 1000001

SBFD template name: -

SBFD backup template name: -

OAM SID: -

Reverse path type: None

BFD Echo: Disabled

Forwarding index: 2150629378

Association ID: 0

Service-class: -

Rate-limit: -

PCE delegation: Disabled

PCE delegate report-only: Disabled

Reoptimization: Disabled

Encapsulation mode: -

Flapping suppression Remaining interval: -

Candidate paths state: Configured

Candidate paths statistics:

CLI paths: 1 BGP paths: 0 PCEP paths: 0 ODN paths: 0

Candidate paths:

Preference : 100

Network slice ID: -

CPathName:

CPathPolicyName:

ProtoOrigin: CLI Discriminator: 100

Instance ID: 0 Node address: 0.0.0.0

Originator: 0, ::

Optimal: Y Flags: V/A

Dynamic: Not configured

PCEP: Not configured

Explicit SID list:

ID: 2 Name: b

Weight: 1 Forwarding index: 2149580805

State: Up State(SBFD): Up

Verification State: -

Path MTU: 1500 Path MTU Reserved: 0

SID list flags: None

Local BSID: -

Reverse BSID: -

<PE1> display bgp routing-table vpnv4 22.22.22.22

BGP local router ID: 1.1.1.1

Local AS number: 100

Route distinguisher: 100:1(aaa)

Total number of routes: 1

Paths: 1 available, 1 best

BGP routing table information of 22.22.22.22/32:

From : 5::5 (5.5.5.5)

Rely nexthop : FE80::1AF8:23FF:FE50:207

Original nexthop: 5::5

Out interface : Ten-GigabitEthernet2/0/1

Route age : 00h28m35s

OutLabel : 3

Ext-Community : <RT: 200:1>, <CO-Flag:Color(00:10)>

RxPathID : 0x0

TxPathID : 0x0

PrefixSID : End.DT4 SID <A:2:2:A:5:0:106:0>

SRv6 Service TLV (37 bytes):

Type: SRV6 L3 Service TLV (5)

Length: 34 bytes, Reserved: 0x0

SRv6 Service Information Sub-TLV (33 bytes):

Type: 1 Length: 30, Rsvdl: 0x0

SID Flags: 0x0 Endpoint behavior: 0x13 Rsvd2: 0x0

SRv6 SID Sub-Sub-TLV:

Type: 1 Len: 6

BL: 64 NL: 16 FL: 16 AL: 16 TL: 0 TO: 0

AS-path : 20

Origin : incomplete

Attribute value : MED 0, localpref 100, pref-val 0

State : valid, internal, best

Source type : local

IP precedence : N/A

QoS local ID : N/A

Traffic index : N/A

Tunnel policy : a

Rely tunnel IDs : 2150629378

# On PE 1, execute the display ip routing-table vpn-instance command. Verify that VPN route 22.22.22.22 is available to CE 2, and the output interface for the route is SRv6 TE policy tunnel a.

Take PE 1 as an example:

<PE1> display ip routing-table vpn-instance aaa

Destinations : 8 Routes : 8

Destination/Mask Proto Pre Cost NextHop Interface

10.1.1.0/30 Direct 0 0 10.1.1.2 XGE2/0/0

10.1.1.2/32 Direct 0 0 127.0.0.1 XGE2/0/0

10.1.1.3/32 Direct 0 0 10.1.1.2 XGE2/0/0

11.11.11.11/32 BGP 255 0 10.1.1.1 XGE2/0/0

20.1.1.0/30 BGP 255 0 5::5 a

22.22.22.22/32 BGP 255 0 5::5 a

127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0

255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0

08-Segment Routing Configuration Guide

About IP L3VPN over SRv6

SRv6 BE mode

SRv6 TE mode

SRv6 TE and SRv6 BE hybrid mode

SRv6 TE and SRv6 BE FRR mode

SRv6 multilevel FRR (primary SRv6 TE path > backup SRv6 TE path > primary SRv6 BE path > backup SRv6 BE path)

SRv6 multilevel FRR (primary SRv6 TE path > primary SRv6 BE path > backup SRv6 TE path > backup SRv6 BE path)

IP L3VPN over SRv6 tasks at a glance

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Prerequisites

Procedure

Restrictions and guidelines

Procedure

About this task

Procedure

About this task

Restrictions and guidelines

Procedure

About this task

Procedure

Specifying a source address for the outer IPv6 header of SRv6-encapsulated packets

Restrictions and guidelines

Procedure

About this task

Procedure

About this task

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Procedure

About this task

Restrictions and guidelines

Procedure

Display and maintenance commands for IP L3VPN over SRv6

Network configuration

Procedure

Verifying the configuration

Network configuration

Procedure

Verifying the configuration

Network configuration

Procedure

Verifying the configuration

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